Lauren Tan workshop XAi Grokbot
1474 segments
Everyone, I am Lauren Laurent Tan. I
guess not many people know my last name.
Uh, I am Potato on Twitter. Uh, potato
with spelled with an E. Um, and I have
been at Cursor for about 5 months. Uh,
previously I was at Meta where I worked
on the React team. Uh, specifically
working on the React compiler, uh, which
was a whole lot of fun. Uh I'm still on
the on the core team and and uh
contributing to open source here and
there. Uh so that that's really nice
that they still let me do that. Uh and
before Meta, I was at Netflix uh where I
was uh both a tech lead and uh I
transitioned to be be an engineering
manager um for about two years. So I've
had a I've have had a lot of experience
going between engineering management and
being an individual contributor. Uh and
I think something I've noticed actually
which is quite interesting is that there
are so many parallels with you know
management skills and how to like manage
agents. Uh and that's actually a big
part about what I wanted to chat with
you and everybody else about today. Um
but yeah that's that's me. Uh I do have
some like very light slides but uh it's
not going to be uh just rambling. So let
me just share my screen
and hope that I don't leak anything. Uh
oh no I need to allow permissions.
>> No worries. Take your time. There's
always tech tech trouble. Uh give me one
second to rejoin.
>> Yeah, go for it.
I see many of you already know Lauren
from the looks of the chat here. Um, so
yeah, it's exciting to to get a chance
to chat with her uh and and go through
some of her her recent work. As you guys
heard, you know, a lot of recent
experience from from Netflix to to Meta
and then now over at Cursor. Uh, we're
going to chat a little bit about
Grockbot as well. So, uh, that'll be
exciting. I don't know if you guys saw
that was a recent release. I think
literally maybe yesterday or the day
before uh from the cursor team which is
kind of like um let's call it like
agents for everyone. You can go check it
out if you want and learn a little bit
more about the product but um but yeah
we'll we'll explore that a little bit
today as well.
All righty. Welcome back.
>> And Lauren, you're just on mute there if
uh you want to hop off of mute if you're
chatting.
>> Yeah, sorry.
>> No worries.
>> It's 2026 and I still don't know how to
use Zoom. [laughter]
>> That's all good.
>> Uh okay. So, I assume you can see my
screen.
>> Yes. Yeah, we're good. Um, so yeah,
today, yeah, I think I think the big
theme for me as I've been using agents
to write code, and I'm sure a lot of you
have had the same experience as well, is
how do you trust it? You know,
especially if you are an engineer that's
been writing code for a very long time,
you have a lot of opinions and lessons
that you've learned about doing good
engineering. And when you see agents
just, you know, winging it and, you
know, guessing, hallucinating,
uh, you know, confidently stating that
they found the smoking gun, uh, for the
hundth time, uh, but it's actually not
the real problem. You lose a lot of
trust. And when you lose when you don't
have much trust in your agents,
I feel like you you really can't get the
most out of them. And for me, the
parallel is like with management. Uh so
if I'm an a manager an engineering
manager of a team and I have a bunch of
you know I have a team of engineers uh
on my team and I don't trust them then
the mode of operation I'm going to be in
is going to be like micromanagement
right I'll have to spend a lot of time
looking over my reports shoulders and
checking that they're doing their work
well you know that they're not shipping
bugs to production
and so I drew this chart cuz uh it's not
it's not a very scientific chart but
like this is how I imagine
myself and my journey through using
agents. So you know like fast forward or
back forward uh or fast back uh fast
backwards like a year or so when you
know nobody was or not many people were
using agents to code. Uh I think you
uh you know get into this mode where you
are
in very heavily in the loop with one or
several like a handful of agents and you
find yourself just constantly figure uh
you know trying to understand what your
agents are doing uh and you're very very
in loop. You're watching every single
output. you are sitting there prompting
um and you really can't parallelize
beyond that because you don't again you
don't have that trust right you can't go
to a 100 agents uh like spawn 100 agents
when you don't even trust the output of
one agent
so over the past 5 months I feel like
I've really been able to uh like ascend
this trust curve and now I'm at the
point where uh I actually have this
Sounds kind of scary to say this and it
makes me sound like a slop artist, but I
I promise I'm not, but I actually have
my agents now um automerging PRs for me.
Uh which is like a wild thing to say,
but um like I woke up today and there
were like 20 PRs landed and I just
reviewed them on Maine like they were
already landed and they were good. Uh so
how did I get to that point is basically
what I wanted to talk about today.
Uh and again like yeah feel free to jump
in if you have questions Colin. Um but
uh oh yeah of course I got to show this
this chart. Uh where uh
oh do do not trust to someone requested
to control my computer. Uh probably
won't do that. Uh but yeah, so this
chart I think I I'm I'm sharing this
chart not to kind of like flex but to
kind of show like the journey like so
you can see like the curve like it sort
of like inversely matches the
contributions I've been able to land at
cursor. So I joined five months ago and
five months ago like I you know my first
month I was like not very productive
because I was obvious you know I was
learning the codebase didn't know what
the heck was going on and as I got more
confident in in my agents uh I've really
been able to kind of ramp up my
productivity. Uh and again like yeah
like last month I shipped a thousand PRs
which is ridiculous. Uh, and then this
month we're only on the 12th. I'm
already at like almost 800 PRs landed.
Uh, so the velocity is definitely high
and you you I'm sure a lot of you will
definitely be questioning like how how
much of this code is actually good. Um,
and I think yeah, like that's definitely
fair to question.
Um, but uh, yeah, I think I think if you
set up your agents well, you can
definitely get to a very similar level.
Um, and so I'm going to talk about how
we do that.
Uh so for me I think I'm curious like I
guess call in your experience as well
but uh for me I think the most important
skill that you should have in your
toolbox when you work with agents is
verification.
Uh and by verification I mean the
ability for an agent to actually run the
code uh or take CPU traces or heap
snapshots or uh you know open an iOS
simulator whatever you know however your
application is exposed to your users it
can do the same thing and uh run it for
real and actually test and verify it
don't work because that's the thing that
really closes the loop. Uh it doesn't
guarantee your agent writes good code.
Uh but it allows them to at least write
correct code. Uh which is a big a really
big step forward for being able to trust
your agent. Um
I will I can share one example that we
have uh within cursor. Uh
oops
where let me open this.
Let's make this uh make me full screen.
There you go. Uh so for the for cursors
agent window uh so this is actually an
interesting story but uh when I joined
cursor 5 months ago uh they're actually
uh well I was supposed to join a
different team. I was supposed to join
like the cloud agents team. Uh but then
since I have a lot of experience working
on react and agents window is a react
application. Uh I was
uh I was asked to basically help out
with uh the agent window work. Uh but um
there wasn't really a lot of like skills
to help me. So I just found myself like
okay uh agents which is going to launch
in like a week right we have a really
tight deadline and um there was uh you
know I was just sitting there like okay
I'm going to open up the performant the
the chrome dev tools and just like take
a trace look at it myself and try to
make sense of this flame graph and keep
in mind I was just like in my first week
so I had no idea what I was looking at
no idea where you know I mean I had some
idea but you know the the code base was
completely fresh to me Uh, and I
realized like my agent had no idea
either, you know, like I would take a
screenshot of the trailer, I would
download trades, I would send it to it,
and it be like, "Yeah, it kind of looks
like this, you know, uh, and it would
like confidently state like it's this
thing." And then I try to fix that and
turns out that's not the actual thing.
So, this was very very slow process. And
if you've ever done any like performance
work yourself or you know just even
development with an agent where you
don't have a verification skill, you are
the verifier, right? You you're the
bottleneck. You you you tell your agent
to do something and then it goes off and
write some code. Then you open up your
you know local dev build and then you
start to say oh you know doesn't work.
Then you got to copy paste screen uh you
know screenshots or console errors or
whatever. uh and then your agent like
slowly kind of like uh you know works
with that and then tries to understand
it and um fix the thing but then you're
constantly just in the loop and and
being a bottleneck. So there's really no
way to parallelize. So the control glass
skill is like one of the first skills I
built uh for cursor. Uh and glass by the
way is the code name for agents window
that we use internally but it's just
cursor I guess. Um, and so this skill uh
is I guess the the the code itself is
not super interesting. Your agent can
very easily make one for you. Uh where
if if you're building an electron app or
a web app or even iOS uh applications,
uh you can teach your agent how to use
like the ChromeDev Tools protocol or
through uh Apple has some utilities as
well for running the simulator and
taking traces and controlling
programmatic control.
as well. Uh so that's really useful. Uh
but one thing I want to talk about is uh
the
this thing
uh where is the read me? Uh so this
skill comes with this very unique
feature called or not feature uh unique
file called a feature map. And so the
story then is like I built this skill
and so now the agent was able to uh
actually run the agent window and take
traces and whatnot. Uh but it had no
idea what what the agent's window was.
So um you know like someone would say
like oh the the left sidebar is like
laggy or something like that or you know
the right side the the PR tab is not
working and the agent would just be like
kind of flailing around. it would spend
a lot of time trying to like look up the
code and you know where is this feature?
How do I actually get to it on the UI
which made it basically completely
useless. Uh you know like we would I
would run this skill locally and you
know it would spawn a dev build uh but
then it just be turnurning like it just
try to click here. It it wouldn't know
how to get to things um and it was just
an awful experience. Uh so who's putting
arrows on my screen? Um so uh yeah this
this feature map has been really useful
uh because it teaches the agent how to
get to all of the features that you
have. Um and in PAC the plugin that I
I've made uh if you search for PAC
cursor on Google you you'll find it. Uh
but there is a create verification skill
in that plug-in where it actually helps
you set up something like this for
yourself. Um including the feature map.
So it will actually explore the code and
build up this initial feature map that
tells your agent how to get to all of
the different features that you have. Uh
and this is extremely powerful because
now like you have these user reports
that come in uh you you can actually map
even like a vague report or even a
screenshot. So we have this uh
internally at cursor where uh we have a
slack channel where you know lots of
people giving us feedback on the agents
window and rockbot and whatnot. Uh, and
often times the report is very bad, like
very low quality, like someone just put
very often we get like a screenshot like
and then someone just says question mark
question mark question mark like what is
this [laughter] and you know like the
without this your agent is like I have
no clue, right? But with a feature map
like this, it has a lot more context and
understanding of how to actually
navigate, how to get to all the
different features. Uh so like you know
example like I guess like the sidebar
like what is the sidebar uh you know
like all the different sub features that
are present in it um like from the user
point of view here's where how do I get
to it all the different keyboard
shortcuts
uh even like the the what do you call it
the DOM elements or yeah like the
attributes that you use for selecting
things through the CDP uh are all there.
So uh again yeah this is like really
really powerful uh for for agents
>> uh and pstack ships uh that create
verification skill but also a maintain
verification skill uh so you can keep
this up to date.
>> Cool. Yeah, I was just going to ask how
you created that. So do you mind sharing
a little bit more about um that that
process in the context of Pstack and
maybe just what Pstack is for the folks
who aren't familiar?
Yeah. So, Pstack is pretty interesting
because uh well, first of all, the name
is kind of goofy. like the P the P in P
sack is like potato potato stack because
I um so uh uh there is a pretty uh
famous person Gary Tan who is the CEO of
Y Combinator and he's come up with this
plugin called GStack uh Gary Stack and
uh funnily enough we share the last name
we have no relations uh but I thought it
would be funny to kind of you know poke
fun at Gary and make Pack back my
version of of of of his plug-in. Uh but
kind of tailor it to my own set of pract
engineering practices.
Uh but I honestly actually never set out
to build PAC. Uh it just started with a
bunch of skills, right? Like I started
with that control glass skill and then I
started with another skill like called
how which I also noticed through like
observing agents. Um, so like you know
in the early days of me, you know,
trying to climb this ladder, I was like
super in the loop and I was basically
nitpicking my agents to an extreme
degree. I was uh I would tell it um you
know this feature has stopped working.
Here's a bug report like why isn't it
working?
And very often the agent would just like
confidently state like oh it has to be
this right it has to be this thing. And
I noticed like when I looked at the
actual tool calls, I noticed it wasn't
actually reading the code that I thought
should be affected. And that made me
just extremely suspicious. And at that
point, I was like, I'm not going to I
can't trust any this agent anymore cuz
it's just it's just completely
hallucinating. And I think
I think it's very easy to just you know
like build up that distrust and not and
kind of feel helpless like you know you
don't know how to help your agents
succeed. But like again I think the the
the management analogy is super helpful
because like imagine if you were a
manager of an engineering team and you
had an engineer on your team who was a
really good coder. No business context
whatsoever. you know they they just you
just hired them and they they onboarded
you know like 5 seconds ago. Uh and so
how do you actually teach that person to
be effective? So how you do that is
through a skill. uh skill being just you
know it's just markdown right but you
know it encodes a lot of information
instructions a lot of uh you can really
draw out a lot of intelligence from an
agent by well some people on Twitter
call it like you know pull the agent to
a different latent space which is kind
of like a fancy way of just saying like
since uh you LLMs are sort of like they
predict the next token uh when you give
it some high quality tokens uh to begin
with then you know it it can kind of
pattern match on like a higher space
that's you know smarter
um so that's like a very interesting
model there but yeah I built Pstack very
very incrementally uh so uh started with
just really observing how agents you
know all the fail different failure
modes of of that agents were having and
every time I saw that I just okay I'm
just going to make that a skill right
like stop hallucinating actually go and
search up, look up the code, use a lot
of sub agents, uh, and yeah, stop
guessing.
>> Yeah, that makes sense. One, one kind of
followup question here, uh, both from
myself and from a bunch of people in the
chat. So, I guess it's two two parts.
So, one is like how do you maintain
these skills? So, like the product
changes over time. Obviously, there's a
lot of people shipping against the
codebase. So, how do these skills get
maintained? Uh and then second to that
is like how do you know when your
verification is is good enough? Uh like
and you know you can trust that the ver
verification loops that you've built are
going to I guess you trust that the
outputs uh when they're done.
>> Uh yeah maybe I'll talk about um I think
there are some related maybe I'll start
with this one first. So like how do I
maintain these skills?
So, um, if you're not familiar with this
concept, an eval [clears throat] is
essentially like a way to, uh, well, I
the mental model I have is like it's
like a unit test for an agent. Um, and,
uh, you can actually make your own eval.
You don't need like a special framework
for them. You can build you can you can
build one depending on like, you know,
how scientific and how rigorous you want
to be. Uh, my screen is red.
>> Yeah, there's a little button. Um,
sorry. Do
>> you mind like disabling the drawing or
something? I I can't see my screen.
>> Yeah, sorry. If you guys could not draw
on the screen, that'd be great. But, um,
there's a little button in the
>> Is that a troll?
>> Yeah, the little drop down.
>> How do I clear?
>> Yeah, you got it. Perfect.
>> Yeah. So, eval
test your skills basically. And actually
in Pstack we ship uh under potato mode
there's a playbook if you search for it
called eval playbook. Um and it's uh
uh it's like not it's actually pretty
pretty rigorous the way it's done. Uh
but um essentially what I do is I spawn
a lot of different sub agents. I have
like my main coordinator agent uh come
up with a rubric for uh what I want the
skill to do. Um, and then it spawns all
these sub aents and it it creates
individual directories for them uh which
are cleverly named to not let the sub
agent know that it's being evaluated
because uh agents can actually tell and
when they do they change their behavior.
Uh, but it does a bunch of stuff like
that to um essentially yeah like test
whether or not the skill I'm making or
changing is actually doing what I think
it does. Um, and one of the really nice
things about cursor is that we are we we
support so many different models. So you
can actually eval your skill across all
sorts of different models um and you
know get a sense of how well it performs
across that different matrix. um
especially for the models that you use.
Uh so I do this a lot. Every time I I
modify a skill, I will run one of these
uh like the Eval playbook uh and make
sure that you know it's actually leading
to a result I want. Uh but I will say
like
maintaining skills is actually pretty
hard. Uh it requires I think a lot of
taste and observation. So, you kind of
need to be very good at being a backseat
driver, you know what I mean? Like, if
you do pair, if you ever done pair
programming, for example, uh, and you
watch a co-orker code and you're just
like, you you could probably do this
better, you know, you could do, you
know, like, why did you not do this,
right? You you ask a lot of questions to
your coworker. And it's kind of a
similar thing here. You like you don't
want to just be a passive observer of
your agent. You want to be very in the
driver seat in the initial stages when
you're building up your own set of
skills. uh you know obviously you can
use something like PAC but if you're
building your own set of skills it's
very I think you know opening up the all
the tool calls and like reading the code
and reading all the uh the agent
behavior and their thinking blocks is a
really great way to see where they they
fail right like what what you know where
are they being done and then you can go
and build a skill for that and then with
verification how you trust it is it's I
think it's also a very similar iteration
loop uh where you know like I actually
did the same process for verifying the
verification skill where I actually get
um so one thing that's interesting about
eval is that you can sort of hill climb
them meaning that uh your eval can
produce a score right uh a score that
you can get your coordinator to produce
uh but also comp uh you can have a judge
agent of a different model to uh kind
cross reference and make sure that the
first model is not being biased, right?
The model that's judging all of the sub
aents that are running the thing. Uh but
you can also like hill climb. So meaning
that you can you can use like /loop in
cursor and you can say okay keep looping
on this eval right until everything is
10 out of 10 as an example. Uh and I did
the same the basically the same approach
with the control skill. And so I kind of
it was very it was very hands-off
actually. Uh so you know I uh I kind of
built I built that skill that way like
the CLI and that skill. Um and over time
it's gotten really good. Uh but yeah it
was definitely not super smooth at the
beginning. It required a lot of
iteration and I think there's an analogy
here for me which is um well I make this
analogy later in a different slide on my
drawing here. Uh but I think of it like
uh you know as a as a engineer now
you're sort of more like you uh like
maybe a manager or the analogy I like is
like you're like a a chef in a
restaurant. Uh you you're the head chef.
Uh you're not cooking all the food
yourself anymore. You have a team of
cooks, right? You have line cooks, you
have a sue chef, you have, you know, all
these different stations.
Um and it's your job to really design
the environment. you know, you you're in
charge of setting up the kitchen. You're
in charge of, you know, like giving
tasks to different people. So,
um yeah, it's a very interesting way of
working. Uh but yeah, that's that's how
I've basically built uh these
verification skills.
>> Yeah, just just one thought there on
like to go try to go one layer deeper.
So, are you let's say we wanted to build
um an eval or a skill for for something
and we wanted to kind of get better on
its own, which is is what I think you're
suggesting. Uh are you doing that in
like a work tree kind of isolated with
like the sub agents and and then the
reviewer agent and and all that? Is it
happening like in some type of cloud
hosted environment? Like what's the the
more the practical steps? If I wanted to
go do this uh and like set up a
verification system for something, what
would I what would I do or where would I
start?
Um I think that uh the best place to
start is local because you can observe
you can definitely observe what your
agents are doing. So, uh, if you're
building a verification skill for
yourself, uh, I would definitely start
local and just have your agent bring up
the application, whether it's like a CLI
or, uh, desktop app or whatever. And so,
you can actually observe, right? You can
see how the agent is interacting with
the the application. You can see it, you
know, how it calls like the different
APIs that that allow it to interact with
the uh the application.
Um but uh for me personally uh I have
basically been kind of all in mostly all
in on cloud agents because they're
extremely powerful. Uh and the really
powerful thing about cursor is the the
cloud agents actually where if you spend
a little bit of time setting up your
environment
these control skills these verification
skills pay a huge amount of dividends
because it's not just something that
makes you as a single engineer better.
It actually levels up your whole team uh
and even your whole company because uh
you can actually start thinking about
cloud agents. change that thing about
automations that automatically do things
like uh I I get I I kind of talk about
this a bit later but I'll just kind of
get into it. uh where where you know for
example like I talk a lot about this
agent we have called Benny right who who
uh you know takes all of the bug reports
that we get and it automatically goes
off in the cloud opens up a cloud uh
it's you know its desktop it runs cursor
in its own computer and it uses the same
control skills to interact with the
application and try to reproduce the bug
uh or the user report right and this is
so so powerful because at once I can
immediately I I get so much information
from this automatically like here in
this example you can see that uh the
benny actually reproduced the bug uh but
it's already fixed on main so it
actually confirms that we fixed this
problem already and all I need to do is
just release another build of of cursor
uh so that's like huge information there
that I didn't have to go off and sit
with an agent you know and spend an hour
trying to figure like is this fixed is
this not fixed
So you you you gain back so much time.
Uh but you know everybody on my team
benefits from this. Everybody at the
company benefits from this. Uh so
definitely think that uh you know
keeping these uh using cloud agents is
super powerful. Uh but yeah it's like a
journey. You have to trust it first
right before you you get to this point.
And that's it goes back to what I was
saying here where you know it's very
hard. It's almost impossible. And I
would definitely encourage you not to
try to jump from, you know, like if
you're still in this zone, you don't
want to jump to like I'm going to spawn
hundred of thousand or thousands of
cloud agents right now because you're
just going to waste a lot of tokens. Um,
and it's going to be extremely
expensive.
>> Yeah. So, just to kind of recap so far,
basically the if we wanted to go on the
journey that you've kind of gone on, it
would be just start with verification.
um building some some skills and some
some ways of determining that the agents
are producing at least like correct code
whether like you said whether it's good
code or not is maybe a separate question
but like it's it's technically solving
the problem by looking at you know stack
traces looking at you know the the
actual behavior in the app and so on um
and then once we trust it locally then
we can start to think about scaling into
the cloud and running more agents that
are picking up signals I guess on their
own right so whether that's like a bug
report that comes in or something they
can go and pick it up and solve the
problem and and give us back a PR and
then maybe the last step is like
automerging the PRs which uh is where
you're at and maybe not where I want to
go.
>> Um and then reviewing them on main but
um is that is that about right?
>> Yeah, exactly. I think yeah that's why I
drew this this uh this curve, right?
Because that this this basically
describes my journey of you know when I
started barely could use a couple agents
and I was just observing every single
thing. I think there's really no
shortcut for going from here to there
because this is really about your
personal level of trust in agents,
right? Um obviously, you know, as a as
engineer, you don't want to just slop
code into production. So, how do you
actually build up that trust takes um a
lot of uh I guess taste and judgment. Um
but uh you know, like I think plugins
like Pstack definitely kind of help you
uh get up to speed much quicker. Uh, and
so I guess it's like if you trust me and
you trust Pstack, then in by extension
you can maybe trust your agents. But if
you don't trust me and I I definitely
would not encourage people to blindly
trust me. Uh, uh, you know, if you build
up your own set of skills that you can
obviously, you know, take a look at PA
and kind of fork it, make it your own,
improve the skills. Definitely encourage
that. Uh but for me it's really all
about it just keeps coming back to
trust. You know every one of us here in
this chat have a different standard for
engineering. Uh and there are different
things that are important for us in our
codebase. And uh when you are able to
encode all of that into skills and you
can verify that your agent is actually
doing them that allows you to really
kind of ascend this curve and um uh you
know start automating things. Uh there's
another piece I wanted to talk about. Um
if there's more
>> Yeah, go for it. I'll I'll pick up more
questions as I go. But
>> yeah, I think there's a third part to
this which I haven't talked about yet
which is kind of an interesting one
which is like refactoring and rewriting
like one of the uh I guess most
controversial one of the most
controversial topics in the industry I
think is like should you rewrite your
app or not? Um because I think engineers
are very prone to this where especially
when you join a company you come in and
you see like the codebase and you're
like oh man this is like who wrote
this code you know it's terrible I want
to rewrite the whole thing there is a
very common inclination and I think a
lot of you know before agents um and I
guess arguably even now people will
definitely discourage you from re
rewriting stuff but I'm actually here to
make a case for why you might want to
consider it.
Um because
I think it really depends. Uh you know,
uh brownfield applications I think are
actually in a pretty good spot,
especially if they're set up well
already. Uh and like recently I've been
talking to some people, but uh you know,
I I was just observing I I just noticed
this parallel, which is that a lot of
big tech company problems are now
everybody's problems. Um, and the big
tech company problem, you know, like
when I was working at Meta, like we had
this giant monor repo, we had like, I
don't know, tens of thousands of
engineers just, you know, like banging
on their keyboards and and shipping code
and
a lot of really great engineers at Meta.
Uh, but, uh, I'll say like, you know,
you'll be surprised that the code
quality is actually not that good.
[laughter] Um, and so I often joke that
like, you know, before AI sloth, we had
human sloth. Um and so uh you know I
think a lot of big tech infra like uh
like what Meta has or Google you know
you know really big tech companies are
actually designed for that where you
you're sort of like you're catering to
the the you know like uh this sounds so
bad to say but like the the least
capable engineer on your team right you
build you build frameworks you build
conventions you build guard rails you
know you restrict credentials so that
you know your intern doesn't wipe your
production database
Um
there's uh you know if you have that
level of infra already I think your
agents can actually already do a very
solid job right because they have the
the guard rails are already in place for
agents to not cause havoc or not cause
too much havoc uh in your codebase um
and you can always add more you know
guardrails. Uh but I think like green
field applications especially are you
know like the brand new applications are
like the biggest risk in my opinion. Uh
and also the greatest opportunity
because you know if you vibe code a
project uh a prototype um like we did
for Grockbot you know Grockbot was spun
up very very very quickly. Um and if you
if you haven't heard of of Grockbot it's
like our a new application we just
launched yesterday. Uh it's it's really
cool. uh lets you orchestrate your
create like individual agents that have
their own identity and you can kind of
orchestrate them. It's super cool.
Definitely check it out. Um but yeah,
that was it's like a very it was a very
green field application like most
prototypes are so like vibe coded very
quickly. Humans were not reading the
code at all. And uh I had this tweet
recently uh where I said something about
organic architecture. Um
maybe I'll find it. Uh but the idea is
that
uh when you have a completely vibe coded
application, you essentially have no
guard rails whatsoever. So uh your
agents
when you give them a task, they will
just solve it in whatever method is the
most convenient. And over time you get
into this uh situation where you have a
code base that is spiraling out of
control because you don't understand it.
Uh your agents understand it I guess in
a way but like they've built something
that is you know optimized for short for
shortcuts. Uh and uh you know it will
you will suffer you'll have a lot of of
issues with that application.
Uh so I think starting your codebase
with uh like very strong constraints is
very much needed uh because like when
you have a codebase that you can trust,
right? when you have guardrails that
actually help you uh uh help your agents
write good code, you can get into the
you know like into this part of the
curve where I I where like I I said you
know I woke up today and I had like 20
PRs merged u by my agents and that's
because I invested a lot a lot of time
uh over 600 PRs I I I calculated
yesterday uh when I refactored all of
Grockbot to this new architecture that
I've been
Um,
and yeah, I've gotten to a point where I
I don't really look I really don't look
at the code anymore. And um, I say that
not just, you know, to sell you tokens,
but because I, you know, it it it took a
lot of work to get to that point. I
spent a lot of tokens to get the
codebase to this point where I no longer
have to look at it. Uh but I'm very
excited because you know of the
potential where you know it's not just
this doesn't just benefit me it benefits
everyone contributing to Grothbot and it
also empowers you know designers and
product managers and you know pe uh even
GTM people to add features to grabbot
and I don't have to worry you know I
don't have to to wake up at night in in
the middle of the night and worry like
oh someone's just merged a perf
regression right I have a ton of
constraints and CI is like it's actually
very annoying to write code in in grabb
but like agents absorb all of that
annoyance.
Um but yeah I'm happy to talk about what
exactly that is. Um
>> yeah I think one question um
>> before we get into the this part here is
just around that element of like what
your your your CI looks like or maybe
some of the constraints and then also
like the average PR size. I saw a
question about that earlier just to give
people you know kind of a a glance. So
it doesn't have to be like
mathematically average but just uh you
know like what generally the size of the
a PR is. Um if it's only a couple lines
of code or you know um yeah
>> um
I think it depends. Uh let me
I'm trying to do this in a way where I'm
not going to like
>> you yeah you don't have to share the
actual number like an actual average.
This this is fine
>> benchmark
>> but like we have so okay this is not
that interesting but uh well fun fact is
that virtualization in Grockbot and in
uh cursor is actually powered by uh
pretext uh which is a sort of new
library that someone's built um that's
really interesting you should you should
check it out but that's not really that
important uh I think the average PR size
I actually don't No, I pro I don't know
if I want to click on these. Uh, I
probably can, but I would say
[clears throat] like they can range
anywhere from a few hundred lines or 50
lines to like a thousand depending on
what the thing is doing. Uh, so like
here I'm actually like deleting a bunch
of files. So I expect that it's just
like mostly deletion. Uh, but yeah, it
kind of varies.
>> There's no like Yeah,
>> there's no like hard cap or hard limit.
Are they're all like 50 line VR?
>> There's no hard cap. Yeah, there's
definitely no hard cap. But I I do
encourage my agents to split up their
work into multiple PRs. Uh I do that
mostly because uh I like I like the idea
of the I guess maybe this is much harder
to do now as in the world of agents and
you have like so many commits, but I
like the idea that you know the git
history is a very rich source of
context. Uh, and I like the I like each
PR to sort of atomically describe what
that small piece of thing is doing,
which also makes it easier for me to
revert changes and like figure out, you
know, oh, I shipped a bug and it's just
it's here, right? It's not in this
40,000 line PR where you who knows what
landed in there.
Uh, but I don't have a hard cap on PR
size.
>> Cool. And then um yeah, also quick
question on like CI. So again, you don't
have to go into like uh the screen share
of like your CI does, but just generally
would you describe what the CI kind of
looks like uh or how strict it is?
>> Uh yeah. So
uh well specifically for Grockbot. So
Dune is the is the sort of cheeky code
code name for the architecture that
we've built for Grockbot. Um the CI
looks pretty annoying because there's
checks for everything. So like literally
I have um uh well if you've written any
React for example you know you know that
one of the biggest foot guns in React is
use effect. Uh so in
uh Dune and in graphbot we've banned use
effect. So Dune is just you can the the
mental model of what Dune is uh you can
kind of think of it as like Nex.js JS
for uh electron apps and it's designed
for agents to write uh and it's like
custom for you know our agent powered
applications. Um so the CI checks are
very like specific to that like you know
don't use use effect. It's it's it's
banned like CI will fail uh and yell at
you. We have like some of the more
interesting ones that people might raise
eyebrows is like I actually ban code
comments as well uh which is very
interesting. Uh, but I've noticed that
99% of the time agents just write code
comments that kind of describe some
historical thing that is actually
totally irrelevant to the code. Um, like
it will often say like, you know, oh,
Lauren said you should never do this and
it's now in in a code comment. I'm like,
what? Like why what that was? I didn't
say that as like a durable, you know,
global rule. I just meant like your this
PR sucks and you should change that
part.
uh agents don't really understand us
that well surprisingly uh and or they
kind of assume too much and they kind of
do things in like very stupid ways. So
like yeah we just ban everything
everything you can imagine like the
agents are bad at we ban. Uh so one
example that we actually suffer a lot in
the agents window is we have uh you know
you know if you've used the agents
window you've definitely seen
performance issues and you know we're
constantly trying to fix them. Uh but
it's like a
it's a never- ending struggle because
there's so many pull requests that get
merged. Every any one of them could just
regress performance or stability or
reliability. Uh you know the agents
window doesn't have this architecture
yet. I plan to do bring this learning
back there and kind of refactor
everything there. Uh but uh it just
regresses super often. uh because uh
there's just one example is like we have
very poor um isolation between
processes. So like on you know on on
electron you have a renderer thread that
renders your UI but you also have like a
main thread that you can run other code
that you know doesn't need to block the
renderer.
Um, but we do a poor job of separating
those things and so often times you just
accidentally have code that gets pulled
into running on the renderer thread and
then all of a sudden you're competing
with the the renderer that you know that
has a very if you want like 60 fps you
have to every frame that gets drawn has
to be done in 16 milliseconds. So very
very small you know deadline per frame
uh if you want you know a very smooth
product. Uh and when you start building
bringing in accidentally bringing in you
know things that are like very
computationally heavy or they have a lot
of IO uh then you just get into like a
lot of jank right your your FPS really
drops you start uh you know losing
frames you get long tasks that take more
than 16 milliseconds and you just get
this really choppy experience.
So all of those patterns that we've
learned basically building electron apps
we've encoded into this framework and it
becomes like a hard failure. So I
literally in in grabbot we literally
have a directory called electron main
electron renderer and we have uh import
uh CI guess where we actually check the
dependency graph to make sure you're not
accidentally importing code from one
directory to another. Uh so that's
enforced by CI um as well as bug bots uh
which is our which cursors um like code
review tool that runs on CI uh you know
in our agents MD it's everywhere like so
I I I I um I have this thing here where
I I talk about like um you know like
there are multiple layers I think for
building a good codebase. Uh obviously
the codebase is one where uh if you have
an architecture like this where it's
extremely strict uh you know the the the
way to build features is very
conventional that's like the strongest
strongest level of enforcement because
agents just love to copy existing
patterns. So uh one example of this in
rockbot is like we have this these
concepts called like a feature and we
have entry points and transcript cards
like oh you know the cards that you see
in the chat these are all like like
nouns I guess in in the framework and so
there's a very conventional way of
creating them and so like a feature is
all in in a single directory as an
example and so all of the code that
contributes to that feature lives in one
directory so it's all coll-located in
one place makes it super easy. You know,
agents don't have to like uh grap around
and try to figure out like where all the
things are. It just looks at the feature
and like, oh, okay, I'm working on the
onboarding feature in Grockbot. Uh I'm
just going to work in this directory.
And for 80% of the work, it's mostly
just very encapsulated there.
[clears throat] But, uh like it's like
very it's like designed again for you
know like the dumbest agent like you
don't have to think, right? the the the
one of the key principles I have for
this framework is like the shortest the
shortest path is the best path.
So uh because that plays exactly to how
agents love to write code is like they
like to take shortcuts really you know
they they'll find the quickest way to
solve the problem. So why not make that
the best way to solve the problem? Uh so
I I probably won't get into all the
specific details. Um and uh the the this
framework is really more of a collection
of ideas and principles rather than
something that will open source. Uh you
can you can you know screenshot this I
guess if you want and uh tell your agent
to uh do some build build something like
this for you too.
Um yeah, but it's really all about the
layers uh you know like the the codebase
is one part with features uh and
directories and you know import or
blocking import dependencies uh that
shouldn't be imported uh but and and it
all enforces that and static analysis.
So like uh there's CI checks, we have a
lot of lints for bad patterns that we
observe. Uh compiler diagnostics,
uh there's also rules and bugbot which
are um I think like three, four, five
are more soft, right? These two actually
make make CI red, right? So that you
know there's a hard constraint where the
agent can't just write crappy code
for rules and skills in Bogbot. Your
agents can still forget, right? You can
still or it may not always consistently
apply them. So I like to layer them, but
I don't I don't like to rely on them as
the only source of enforcement because
it's very very soft, right? And if you
if you only have rules and bug bot and
skills and a style guide for your code,
you will it's only a matter of time
before your codebase looks like complete
trash. I'm sorry to say that but uh I
definitely recommend yeah like you know
investing in you know things that can be
hard and forced right and this is why
you know maybe the choice of tech stack
that you use is also very important. Um
like I think for example Rust is sort of
making you know it's like getting super
popular again uh because the compiler is
so strict right the compiler enforces so
many different things you know there's a
borrow checker that you have to appease
and if as long as you make sure your
agents don't write unsafe code blocks uh
you can more or less feel somewhat
confident that if the code compiles it
probably works and it's good. Uh but you
see it gives you that level of trust and
confidence that you as a human engineer
no longer need to go and check it
yourself. You know you you rely on code
and static analysis to actually make
that uh a lot smoother. Um, and I I
guess the worst part, the worst place to
be in is if you are stuck in code review
land where you actually enforce all of
the constraints, the invariance in your
codebase by literally the human person
saying, you know, reading the code and
like, okay, you should not do this,
right?
Every time you have to do that, you
should consider that as a code smell,
like a anti- pattern. And you should
say, okay, instead of me commenting on
the PR, how do I turn this into a hard
rule, right? How do I turn this into a
lint rule? How do I turn this into a CI
failure? Or how do I even categorically
eliminate this problem uh entirely? Uh I
I can talk about another migration I've
done, but I'll probably pause here.
>> Sure.
>> Yeah. I feel like that's that's where I
am to be honest is is what you're
describing right now which is that like
I don't have all of these rules. So I
have some things to go do after this
session in terms of being able to scale
my agents. I'm I'm definitely on like
the uh you know maybe a couple of
parallel ones locally stage. So like two
to three locally and I'm sure most
people here are on the same. So uh yeah
I know we only couple minutes left.
Lauren, was there anything else that you
wanted to to highlight? I obviously
there's lots of questions so I can grab
more but I want to give you a few
minutes if there's anything else you
want to talk about.
>> I think I've been yapping for quite a
lot so I maybe let's just do questions.
>> Okay, cool. Uh one question that had uh
a couple of uh came up a couple times
was just around like token usage.
>> So the the question is like is is what
you're describing a realistic thing for
people who are on you know uh a normal
set of token usage. They don't have you
know basically unlimited tokens uh to
work with.
I think that's a really good point. I
mean like obviously, you know, I work at
a AI lab where we have unlimited tokens.
So, uh I definitely cannot
say that, you know, this is something
everyone should do in the exact same way
that I did it. I think it's possible to
get to this point without, you know,
breaking the bank.
But you know if you're like an
engineering leader or you know you're
you you have a startup that you lead um
I think to me it's a question of ROI um
and it's like uh yes you spend a lot of
money on tokens in the upfront stage you
know like refactoring your code base is
going to take a lot of tokens uh adding
all these things uh is going to take a
bunch of tokens but if we're heading to
a world where agents are writing all the
code and you know You want to be very
lean, right? You don't want to have to
hire, you don't want to be, you don't
want to become like meta, right? Like I
mean like in terms of you don't want to
become a 10,000 person engineering org
because I mean that's a cool problem to
have, but also you you have so much
overhead. There's like planning, you
know, like you it's it's a personally I
I wouldn't uh it it's not super fun, but
um I think you want to stay very nimble,
right? And you want to you want to be
like agents are all about allowing you
to do things that you couldn't do
before. That's really to me like the
value of agents, you know, it's not just
storing tokens on every single little
thing, but um to me like the thing I
couldn't do before is like enforce this
level of constraints in a codebase by
myself, right? Like I'm just a single
person, you know? Uh it would have taken
me years to build this framework uh and
do all the refactoring and test
everything myself and verify you know
like run imagine if there it was just me
right no in in pre- agent era just like
running you know by it would take me so
long right and my salary is pretty high
right like so you know the the question
I think an engineering leader might have
is just then you know like what is
there's a trade-off of do to hire
someone to do this or do you spend the
tokens to set up a code base so that
even the the most naive, right, the
dumbest agents can do a good job. And
when you actually get to this point,
like even agents that are not, you know,
fable size do an excellent job of
writing code. And this pays a lot of
dividends as well for me personally
where I've empowered not just myself but
again like PMs, designers, engineers who
are not familiar with Grockbot to just
contribute in a way that is sustainable.
So I think yeah it's definitely like a
trade-off for sure. You know like
nothing is like free for sure. Uh and
tokens are pretty expensive. Uh but oh
actually uh I I I don't know how many of
you have seen this but we actually
announced Grock 4.6 today. So very
exciting finally out. Um so yeah Gro 4.6
would be like a great it was very very
smart. Uh it's really good on the on the
benchmarks. Uh and it's the same the
tokens uh well uh I hopefully I'm not
saying this incorrectly but uh I believe
the cost per token is the same as 4.5.
So you're actually getting more
intelligence for the same cost. Uh I
think this is an area that cursor tries
to cursor and SpaceX AI try to really
optimize for like that heredto frontier
of you know cost versus intelligence. Uh
you know we don't necessarily want to
build the biggest model ever because
that is extremely expensive to run. It's
really about like how do you find that
sweet spot right? you don't you don't
need a giant model, but it's just super
smart, right? And it's not very
expensive for inference.
Uh but um yeah, I think to kind of round
it up, um I think it's like a it's it's
there's a if you do your own analysis, I
feel like it's pretty positive. It it'll
be pretty positive that the ROI you get
from investing in stuff like this uh
just empowers not just yourself, but
your whole team to be so much more
productive, right? Right? Like imagine
if you have an army of engineers like me
who are shipping so much improvements
and and bug fixes uh you know every day,
right? Like that is pretty exciting.
>> Cool. Uh one last question before we
wrap up. This one is for the people in
product on the on the call.
>> So let's say we do have an army of
engineers who are shipping like Lauren.
I'm just curious like how is the product
team or other functions of your company
keeping up given that like if you're
shipping so quickly have are they using
AI more to do their jobs like as much as
you can speak to that obviously you
don't have like you're not in that role
but just curious about how that works.
Um I think this is where grabbot has
been actually exceedingly powerful. Uh
where so before grabbot like you know uh
obviously cursor only had cursor like we
only had agents window we had a CLI we
had an IDE and these are really like
power user tools right like de they're
designed for developers so it's very
very developerentric you can do
knowledge work in them but it like the
UI is not really optimized for that. So
we actually didn't really have uh well I
think like a lot of people like you know
GTM product like they might have used
cursor uh to do their work but it
definitely wasn't like a delightful
experience for them. Um I think now with
Grogbot
uh it's become Grogbot is basically like
the Kusher moment for people who are not
in tech in my opinion like it's like
it's like a very very accessible way to
use agents in a very comfortable very
familiar interface. It looks like
iMessage
um and it's very fun to you know you can
give your agent a fun name. uh you can
have you can kind of do orchestration
with in a very like natural way where
you can sort of you know each agent is
like a person right and now you got a
team of agents like working on you have
one one agent per account that you
manage as an example or if you're a PM
you have you know you can have an agent
that summarizes all the work that Lauren
did last night and then now you know
what I did right so I think our PMs are
leveraging that a lot and they're
shipping code too uh so you know like
often times they will just say oh here's
a bug I fixed can you look at it and
then I'll go review it and actually it's
just perfect. I'm like okay stamp. Uh so
uh that I think that shows that you know
the the Dune architecture is holding up
right the all the the really strict
constraints allow people who are not
experts in engineering to contribute at
a high level. Uh so I'm I feel like I'm
already seeing that pay off a lot where
uh you know designers and PMs are just
able to to to ship features directly.
Um, and that just makes the Grockbot
team super fast, right? Where we can
ship so quickly. Um, and we have a lot
planned, so I'm very excited uh to, you
know, uh to to ship more ship more
stuff.
>> Yeah, that's awesome. We are at time, so
uh I guess Lauren, if if folks want to
support you, maybe go try out Grockbot,
try out uh 46 and uh you know, get get
provide some feedback. But yeah, this
was awesome. really appreciate you
taking the time. Uh thanks everyone for
all the messages in the chat. Lots of
good questions. I know we didn't get
through everything, but as I kind of
said at the top, way more questions than
than we could get through, but uh yeah,
really really thanks thanks for for
joining. Thanks everyone for joining and
hopefully you enjoyed the session.
>> Yep.
>> All right.
>> Yeah, I see see thanks for having me and
uh if you have any more questions yet,
just DM me on Twitter. I'll I'll open
them up. I guess I'll let the
>> You're gonna get a lot of DMs.
>> I'll open the floodgates. So yeah, DM
me. Maybe I'll do like a Twitter space
at some point as well for more
questions. But really appreciate
everyone for showing up. Uh, you know,
taking an hour out of your day.
>> Yeah. All right. Thanks all. I'll see
you the next one.
>> Okay. Thanks everyone. Bye.
Ask follow-up questions or revisit key timestamps.
Lauren Laurent Tan, a software engineer at Cursor with experience at Meta and Netflix, discusses the crucial importance of building trust with AI agents. She explains that shifting from a 'micromanager' mindset to a 'head chef' mindset—where the engineer designs the environment and constraints rather than writing every line of code—allows for massive increases in productivity. Key takeaways include the necessity of 'verification' (enabling agents to run and test code themselves), the use of 'feature maps' to provide context, and implementing strict 'guardrails' through CI checks, linting, and architectural constraints to maintain codebase quality while automating PRs.
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