Francois Chollet is leaving Google

Hi HN, Francois here. Happy to answer any questions!

Here's a start --

"Did you get poached by Anthropic/etc": No, I am starting a new company with a friend. We will announce more about it in due time!

"Who uses Keras in production": Off the top of my head the current list includes Midjourney, YouTube, Waymo, Google across many products (even Ads started moving to Keras recently!), Netflix, Spotify, Snap, GrubHub, Square/Block, X/Twitter, and many non-tech companies like United, JPM, Orange, Walmart, etc. In total Keras has ~2M developers and powers ML at many companies big and small. This isn't all TF -- many of our users have started running Keras on JAX or PyTorch.

"Why did you decide to merge Keras into TensorFlow in 2019": I didn't! The decision was made in 2018 by the TF leads -- I was a L5 IC at the time and that was an L8 decision. The TF team was huge at the time, 50+ people, while Keras was just me and the open-source community. In retrospect I think Keras would have been better off as an independent multi-backend framework -- but that would have required me quitting Google back then. Making Keras multi-backend again in 2023 has been one of my favorite projects to work on, both from the engineering & architecture side of things but also because the product is truly great (also, I love JAX)!

Congratulations Francois! Thanks for maintaining Keras for such a long time and overcoming the corporate politics to get it where it is now.

I've been using it since early 2016 and it has been present all my career. It is something I use as the definitive example of how to do things right in the Python ecosystem.

Obviously, all the best wishes for you and your friend in the new venture!!

Will you come back to Europe?

> "Why did you decide to merge Keras into TensorFlow in 2019": I didn't! The decision was made in 2018 by the TF leads -- I was a L5 IC at the time and that was an L8 decision. The TF team was huge at the time, 50+ people, while Keras was just me and the open-source community. In retrospect I think Keras would have been better off as an independent multi-backend framework -- but that would have required me quitting Google back then.

The fact that an "L8" at Google ranks above an OSS maintainer of a super-popular library "L5" is incredibly interesting. How are these levels determined? Doesn't this represent a conflict of interest between the FOSS library and Google's own motivations? The maintainer having to pick between a great paycheck or control of the library (with the impending possibility of Google forking).

I will still be US-based for the time being. I'm seeing great things happening on the AI scene in Paris, though!

> I was a L5 IC at the time and that was an L8 decision

omg, this sounds like the gigantic, ossified and crushing bureaucracy of a third world country.

It must be saying something profound about the human condition that such immense hierarchies are not just functioning but actually completely dominating the landscape.

Hi François, just wanted to take the opportunity to tell you how much your work has been important for me. Both at the start, getting into deep learning (both keras and the book) and now with keras3 as I'm working to spread DL techniques in economics. The multi-backend is really a massive boon, as it also helps ensure that the API would remain both standardised and simple, which is very helpful to evangelise new users that are used to higher-level scripting languages as my crowd is.

In any case, I just want to say how much an inspiration the keras work has been and continues to be. Merci, François !

Congrats, François, and good luck!

Q: The ARC Prize blog mentions that you plan to make ARC harder for machines and easier for humans. I'm curious if it will be adapted to resist scaling the training dataset (Like what BARC did -- see my other comment here)? As it stands today, I feel like the easiest approach to solving it would be BARC x10 or so, rather than algorithmic inventions.

Right, one rather uninteresting line of approaches to ARC consists of trying to anticipate what might be in the test set, by generating millions of synthetic tasks. This can only work on relatively simple tasks, since the chance of task collision (between the test set and what you generate) is very low for any sophisticated task.

ARC 2 will improve on ARC 1 by making tasks less brute-forceable (both in the sense of making in harder to find the solution program by generating random programs built on a DSL, and in the sense of making it harder to guess the test tasks via brute force task generation). We'll keep the human facing difficulty roughly constant, which will be controlled via human testing.

Thanks for the kind words -- glad Keras has been useful!

L8 at Google is not a random pecking order level. L8s generally have massive systems design experience and decades of software engineering experience at all levels of scale. They make decisions at Google which can have impacts on the workflows of 100s of engineers on products with 100millions/billions of users. There are less L8s than there are technical VPs (excluding all the random biz side VP roles)

L5 here designates that they were a tenured (but not designated Senior) software engineer. It doesn't meant they don't have a voice in these discussions (very likely an L8 reached out to learn more about the issue, the options, and ideally considered Francois's role and expertise before making a decision), it just means its above their pay grade.

I'll let Francois provide more detail on the exact situation.

This is just the standard Google ladder. Your initial level when you join is based on your past experience. Then you gain levels by going through the infamous promo process. L8 represents the level of Director.

Yes, there are conflicts of interests inherent to the fact that OSS maintainers are usually employed by big tech companies (since OSS itself doesn't make money). And it is often the case that big tech companies leverage their involvement in OSS development to further their own strategic interests and undermine their competitors, such as in the case of Meta, or to a lesser extent Google. But without the involvement of big tech companies, you would see a lot less open-source in the world. So you can view it as a trade off.

Thank you!

> How are these levels determined?

I have no knowledge of Google, but if L5 is the highest IC rank, then L8 will often be obtained through politics and playing the popularity game.

The U.S. corporate system is set up to humiliate and exploit real contributors. The demeaning term "IC" is a reflection of that. It is also applied when someone literally writes a whole application and the idle corporate masters stand by and take the credit.

Unfortunately, this is also how captured "open" source projects like Python work these days.

just wanna take this chance to say a huge thank you for all the amazing work you’ve done with Keras!

back in 2017, Keras was my introductory framework to deep learning. it’s simple, Pythonic interface made finetuning models so much easier back then.

also glad to see Keras continue to thrive after getting merged into TF, especially with the new multi-backend support.

wishing you all the best in your new adventure!

Hi Francois, congrats on leaving Google!

ARC and On the Measure of Intelligence have both had a phenomenal impact on my thinking and understanding of the overall field.

Do you think that working on ARC is one of the most high leverage ways an individual can hope to have impact on the broad scientific goal of AGI?

Hey,I really liked your little book of deep learning, even though I didn't understand everything in it yet. Thanks for writing it!

That's what I plan on doing -- so I would say yes :)

Enjoy the book!

Bureaucracy as per Weber is simply 'rationally organized action'. It dominates because this is the appropriate way to manage hundreds of thousands of people in a impersonal, rule based and meritocratic way. Third world countries work the other way around, they don't have professional bureaucracies, they only have clans and families.

It's not ossified but efficient. If a company like Google with about ~180.000 employees were to make decisions by everyone talking to everyone else you can try to do the math on what the complexity of that is.

effective, maybe. efficient... I would not be so sure.

what does this comment even mean? how does an L8 telling an L5 to do something a reflection of a "gigantic, ossified and crushing bureaucracy of a third world country."? i can't figure out the salience of any of the 3 adjectives (nor third world).

> human condition that such immense hierarchies are not just functioning but actually completely dominating the landscape.

...how else do you propose to dominate a landscape? do you know of any landscapes (real or metaphorical) that are dominated by a single person? and what does this have to do with the human condition? you know that lots of other animals organize into hierarchies right?

if this comment weren't so short i'd swear it was written by chatgpt.

Hi Francois, I'm a huge fan of your work!

In projecting ARC challenge progress with a naive regression from the latest cycle of improvement (from 34% to 54%), it seems that a plausible estimate as to when the 85% target will be reached is sometime between late 2025 & mid 2026.

Supposing ARC challenge target is reached in the coming years, does this update your model of 'AI risk'? // Would this cause you to consider your article on 'The implausibility of intelligence explosion' to be outdated?

This roughly aligns with my timeline. ARC will be solved within a couple of years.

There is a distinction between solving ARC, creating AGI, and creating an AI that would represent an existential risk. ARC is a stepping stone towards AGI, so the first model that solves ARC should have taught us something fundamental about how to create truly general intelligence that can adapt to never-seen-before problem, but it will likely not itself be AGI (due to be specialized in the ARC format, for instance). Its architecture could likely be adapted into a genuine AGI, after a few iterations -- a system capable of solving novel scientific problems in any domain.

Even this would not clearly lead to "intelligence explosion". The points in my old article on intelligence explosion are still valid -- while AGI will lead to some level of recursive self-improvement (as do many other systems!) the available evidence just does not point to this loop triggering an exponential explosion (due to diminishing returns and the fact that "how intelligent one can be" has inherent limitations brought about by things outside of the AI agent itself). And intelligence on its own, without executive autonomy or embodiment, is just a tool in human hands, not a standalone threat. It can certainly present risks, like any other powerful technology, but it isn't a "new species" out to get us.

Hi! As someone who spent the last month pouring myself into the ARC challenge (which has been lots of fun, thanks so much for creating it), I'm happy to see it made harder, but please make it harder by requiring more reasoning, not by requiring more human-like visual perception! ARC is almost perfect as a benchmark for analogical reasoning, except for the need for lots of image processing as well. [Edit: however, I've realised that perception is representation, so requiring it is a good thing.]

Any plan for more validation data to match the new harder testset?

Bureaucracies are certainly impersonal, but you'd be at a loss to find one that's genuinely rule based and meritocratic. To the extent that they become remain rule based they are no longer effective and get routed around. To the extent that they're meritocratic, the same thing happens with networks of influence. Once you get high enough, or decentralised enough bureaucracies work like any other human tribes. Bureaucracies may sometimes be effective ways to cut down on nepotism (although they manifestly fail at that in my country), but they're machines for manifesting cronyism.

> > I was a L5 IC at the time and that was an L8 decision

> omg, this sounds like the gigantic, ossified and crushing bureaucracy of a third world country.

No, it sounds like how most successful organizations work.

Depends on what you’re trying to achieve.

Small organizations define efficiency based on time to make number go up/down. Meanwhile, if something bad happens at 2am and no one wakes up - whatever there we’re likely no customers impacted.

Larger organizations are really efficient at ensuring the p10 (ie worst) hires are not able to cause any real damage. Every other thing about the org is set up to most cost effectively ensure least damage. Meanwhile, numbers should also go up is a secondary priority.

> It's not ossified but efficient.

These are just assertions. Efficient compared to what?

> If a company like Google with about ~180.000 employees

Why should an organization even have 180000 employees? What determines the distribution of size of organizational units observed in an economy?

And given an organization's size, what determines the height of its "pyramid"?

The fact that management consultancies are making (in perpetuity) a plush living by helping reduce "middle management layers" tells you explicitly that the beast has a life of its own.

Empire building and vicious internal politics that are disconnected from any sense of "efficiency" are pretty much part of "professional bureaucracies" - just as they are of the public sector ones. And whether we are clients, users or citizens we pay the price.

The IC ladder at Google grows from L3 up to L10.

An L8 IC has similar responsibilities as a Director (roughly 100ish people) but rather than people, and priority responsibility it is systems, architecture, reliability responsibility.

I personally can't relate, but that's because I've never been in any organization at that scale, biggest companies I've been had employees numbering in the thousands, of which IT was only hundreds at most. There you go as far as having scrum teams with developers, alongside that one or more architect, and "above" that a CTO. Conversely, companies like Google have tens of thousands of people in IT alone.

But likewise, since we're fans of equality in my country, there's no emphasis on career ladders / progression; you're a developer, maybe a lead developer or architect, and then you get to management, with the only distinguishing factor being your years of experience, length of your CV, and pay grade. Pay grade is "simply" bumped up every year based on performance of both you personally and the company as a whole.

But that's n=1 experience, our own company is moving towards a career ladder system now as well. Not nearly as extensive as the big companies' though.

L5 isn't the highest IC level at Google. Broadly would go up to L10, but the ratio at every level is ~1:4 or 1:5 b/w IC levels.

The L7/L8 level engineers I've spoken or worked with have definitely earned it - they bring to bear significant large scale systems knowledge and bring it to bear on very large problem statements. Impact would be felt on billion$ impact wise.

well others seems to be getting the meaning (whether they agree or not is another matter), so you might be too habituated to the "L" world to bother understanding?

> if this comment weren't so short i'd swear it was written by chatgpt.

ditto

I’m really going through it, trying to get legacy Theano and TensorFlow 1.x models from 2016 running on modern GPUs due to compatibility headaches due to OS, NVIDIA CUDA, CuDNN, drivers, docker, python, and package/image hubs all contributing their own roadblocks to actually coding. Ideally we would abandon this code, but we kind of need it running if we want to thoroughly understand our new model's performance on unseen old data, and/or understand Kappa scores between models. Will the move towards freeing Keras from TF again potentially reintroduce version chaos, or will it future proof it from that? Do you see a potential for something like this to once again befall tomorrow's legacy code relying on TF 1.x and 2.x?

From one François to an other, thank you for you work, and all the best with your next endeavor!

Your various tutorials and your book "Deep Learning with Python" have been invaluable in helping me get up to speed in applied deep learning and in learning the ropes of a field I knew nothing about.

Most large organizations are hugely bureucratic regardless of whether they are successful or not :-)

In any case the prompt for the thread is somebody mentioning their (subjective) view that the deep hiearachy they were operating under, made a "wrong call".

We'll never know if this true or not, but it points to the challenges for this type of organizational structure faces. Dynamics in remote layers floating somewhere "above your level" decide the fate of things. Aspects that may have little to do with any meritocracy, reasonableness, fairness etc. become the deciding factors...

Hi Francois,

any chance to work or at least intern (remote, unpaid) with you directly? Would be super interesting and enriching.

Keras is now standalone and multi-backend again. Keras weights files from older versions are still loadable and Keras code from older versions are still runnable (on any backend as long as they only used Keras APIs)!

In general the ability to move across backends makes your code much longer-lived: you can take your Keras models with you (on a new backend) after something like TF or PyTorch stops development. Also, it reduces version compatibility issues, since tf.keras 2.n could only work with TF 2.n, but each Keras 3 version can work with a wide range of older and newer TF versions.

>These are just assertions. Efficient compared to what?

Compared to numerous small companies of the aggregate same size. It's not just an assertion, Google (and other big companies) produces incredibly high rates of value per employee and goods at extremely low costs to consumers.

>Why should an organization even have 180000 employees? What determines the distribution of size of organizational units observed in an economy?

Coase told us the answer to this[1]. Organizations are going to be as large as they can possibly be until the internal cost of organization is larger than the external costs of transaction with other organizations. How large that is depends on the tools available to organize and the quality of organization, but tends larger over time because management techniques and information sharing tools become more sophisticated.

The reason why large organizations are efficient is obvious if you turn it on its head. If we were all single individual organizations billing each other invoices we'd have maximum transaction costs and overhead. Bureaucracy and hierarchies minimize this overhead by turning it into a dedicated disciplines and rationalize that process. A city of 5 million people, centrally administered produces more economic value than a thousand villages with the same aggregate population.

[1] https://onlinelibrary.wiley.com/doi/10.1111/j.1468-0335.1937...

Er, isn't that by François Fleuret, not by François Chollet?

Economic arguments almost always apply strictly to idealized worlds where each individual calculates the pennies for each action etc. The degree to which such deductions apply to the real world varies. In this case large bureaucracies are everywhere in the public sector as well, where, at least to first order, price mechanisms, profit maximization etc. are not the driving force. Hierarchy of some form is innate to human organization, this is not the point.

The alternative to a large organization with a sky-high hierarchy is not an inefficient solopreneur but a smaller organization with (possibly) a flater hierarchy. Even strictly within the Coase logic the "external cost" can be artificially low (non-priced externalities [1]), ranging from the mental health of employees, to the impact of oligopolistic markets on society's welfare etc. This creates an unusually generous buffer for "internal costs".

[1] https://en.wikipedia.org/wiki/Externality

> I was a L5 IC at the time

Kudos to Google for hiring extremely competent people, but I'm surprised that the creator and main architect of Keras hadn't been promoted to Staff Engineer at minimum.

Thanks for that, and thanks for Keras

Another happy Keras user here (under TF - but even before with Theano)

at certain levels in the corporate ladder, it's all about who or whom you glaze to get to that next level.

actual hard skills are irrelevant

What are some AI frameworks you really like working with? Any that go overlooked by others?

Hierarchy aside, I am surprised the literal author and maintainer of the project, on Google’s payroll no less, was not consulted on such a decision. Seems borderline arrogant.

Hello, Francois! My question isn't related directly to the big news, but to a lecture you gave recently https://www.youtube.com/watch?v=s7_NlkBwdj8&ab_channel=Machi... At 20:45 you say "So you cannot prepare in advance for ARC. You cannot just solve ARC by memorizing the solutions in advance." And at 24:45 "There's a chance that you could achieve this score by purely memorizing patterns and reciting them." Isn't that a contradiction? The way I understand it on one hand you are saying ARC can't be memorized on the other you are saying it can?

My go-to DL stack is Keras 3 + JAX. W&B is a great tool as well. I think JAX is generally under-appreciated compared to how powerful it is.

> In this case large bureaucracies are everywhere in the public sector as well, where, at least to first order, price mechanisms, profit maximization etc. are not the driving force.

I'd say that large bureaucracies are endemic to the public sector in large part because they can't use efficient price or profit mechanisms.

A firm doesn't typically operate like a market internally, but instead it operates like a command economy. Orders flow from the top to be implemented at lower levels, feedback goes the other way, and divisions should generally be more collaborative than competitive.

Bureaucracy manages that command economy, and some amount of it is inevitable. However, inevitability does not mean infallibility, and bureaucracies in general are prone to process orientation, empire-building, and status-based backstabbing.

> ranging from the mental health of employees

Nitpick: I think that disregard of employee mental health is bad, but I don't think it's an unpriced externality. Employees are aware of their own mental health and can factor it into their internal compensation/quality-of-life tradeoff, staying in the job only when the salary covers the stress.

Congrats, good luck with your new company!

I have one question regarding your ARC Prize competition: The current leader from the leaderboard (MindsAI) seems not to be following the original intention of the competition (fine tune a model with millions of tasks similar with the ARC tasks). IMO this is against the goal/intention of the competition, the goal being to find a novel way to get neural networks to generalize from a few samples. You can solve almost anything by brute-forcing it (fine tunning on millions of samples). If you agree with me, why is the MindsAI solution accepted?

> Aspects that may have little to do with any meritocracy, reasonableness, fairness etc. become the deciding factors...

If you're not presenting an alterative system, then is it still the best one you can think of?

Where's the evidence of it being ossified?

I agree with all of that.

I think the main differences between private sector bureacracy and public sector bureaucracy are:

- I'm forced to fund the public sector bureaucracy

- There's no competitive pressure putting a lid on public sector bureaucracy

I had never thought about how close perception and reasoning are from a computational point of view, the parts of ARC that we call "reasoning" seem to just be operations that the human brain is not predisposed to solve easily.

A very interesting corollary is that the first AGIs might be way better thinkers than humans by default because of how they can seamlessly integrate new programs into their cognition in a perfect symbiosis with computers.

Thank you for Keras! Working with Tensorflow before Keras was so painful. When I first read the news I was just thinking you would make a great lead for the tools infra at a place like Anthropic, but working on your own thing is even more exciting. Good luck!

> ... was not consulted on such a decision ...

What Francois wrote suggests he was overruled.

It takes a while to get promoted, but he certainly did not leave as L5

There have been countless proposals for alternative systems. Last-in, first-out from memory is holacracy [1] "Holacracy is a method of decentralized management and organizational governance, which claims to distribute authority and decision-making through a holarchy of self-organizing teams rather than being vested in a management hierarchy".

Not sure there has been an opportunity to objectively test what are the pros and cons of all the possibilities. The mix of historical happenstance, vested interests, ideology, expedience, habit etc. that determines what is actually happening does not leave much room for observing alternatives.

[1] https://en.wikipedia.org/wiki/Holacracy

Google being arrogant? Say it isn’t so!

> Economic arguments almost always apply strictly to idealized worlds where each individual calculates the pennies for each action etc. The degree to which such deductions apply to the real world varies.

But the assumption that individuals actually make that calculation is not necessary for economic models to be useful.

For example, players who act in a game theoretically optimal way in some game will, over the long run, dominate and displace players who don't.

This is true even if those players don't actually know any game theory.

Down leveling is a pretty common strategy larger companies use to retain engineers.

But how do you know that Holocracy is more reasonable or fair? The Wikipedia article you linked isn't exactly glowing!

François as a contestant of ARC prize ?! For real ?

ARC as a stepping-stone for AGI? For me, ARC has lost all credibility. Your white paper that introduced it claimed that core knowledge priors are needed to solve it, yet all the systems that have any non-zero performance on ARC so far have made no attempt to learn or implement core knowledge priors. You have claimed at different times and in different forms that ARC is protected against memorisation-based Big Data approaches, but the systems that currently perform best on ARC do it by generating thousands of new training examples for some LLM, the quintessential memorisation-based Big Data approach.

I too, believe that ARC will soon be solved: in the same way that the Winograd Schema Challenge was solved. Someone will finally decide to generate a large enough dataset to fine-tune a big, deep, bad LLM and go to town, and I do mean on the private test set. If ARC was really, really a test of intelligence and therefore protected against Big Data approaches, then it wouldn't need to have a super secret hidden test set. Bongard Problems don't and they still stand undefeated (although the ANN community has sidestepped them in a sense, by generating and solving similar, but not identical, sets of problems, then claiming triumph anyway).

ARC will be solved and we won't learn anything at all from it, except that we still don't know how to test for intelligence, let alone artificial intelligence.

The worst outcome of all this is the collateral damage to the reputation of symbolic program synthesis which you have often name-dropped when trying to steer the efforts of the community towards it (other times calling it "discrete program search" etc). Once some big, compensating, LLM solves ARC, any mention of program synthesis will elicit nothing but sneers. "Program synthesis? Isn't that what Chollet thought would solve ARC? Well, we don't need that, LLMs can solve ARC just fine". Talk about sucking out all the air from the room, indeed.

There is a competitive pressure on public center bureaucracy it is the competition for resources between countries sometimes it is was sometimes it is not but ultimately the public sector will be punished from the outside.

Every company I've seen that has tried Holacracy abandoned it shortly after.

Could you elaborate on this? how does being down-leveled make an engineer less likely to leave?

Wow, you're the most passionate hater of ARC that I've seen. Your negativity seems laughably overblown to me.

Are there benchmarks that you prefer?

Perception is the representation of raw inputs into a form useful for further processing, but it is not a feed-forward computation. You repeatedly re-represent what you see as you keep looking. Particularly something like an ARC puzzle where you have to find a representation that reveals the pattern. That's what my ARC solver is about (I did not finish it for the deadline).

> A very interesting corollary is that the first AGIs might be way better thinkers than humans by default

I agree at least this far. Human System 2 cognition has some very severe limitations (especially working memory, speed, and error rate) which an AGI probably would not have. Beyond fixing those limitations, I agree with François that we shouldn't assume there aren't diminishing intelligence returns to better mental architectures.

> the goal being to find a novel way to get neural networks to generalize from a few samples

Remove "neural networks". Most ARC competitors aren't using NNs or even machine learning. I'm fairly sure NNs aren't needed here.

> why is the MindsAI solution accepted?

I hope you're not serious. They obviously haven't broken any rule.

ARC is a benchmark. The point of a benchmark is to compare differing approaches. It's not rigged.

you... are correct. Shame on me. Still a good book!

I also don't understand why MindsAI is included. ARC is supposed to grade LLMs on their ability to generalize i.e. the higher score the more useful they are. If MindsAI scores x2 than the current SOTA then why are we wasting our $20 on inferior LLMs like ChatGPT adn Claude when we could be using the one-true-god MindsAI? If the answer is "because it's not a general-purpose LLM" then why is ARC marketed as the ultimate benchmark, the litmus test for AGI (I know I know, passing ARC doesn't mean AGI, but the opposite is true, I know)?

I believe the MindsAI solution does feature novel ideas that do indeed lead to better generalization (test-time fine-tuning). So it's definitely the kind of research that ARC was supposed to incentivize -- things are working as intended. It's not a "hack" of the benchmark.

And yes, they do use a lot of synthetic pretraining data, which is much less interesting research-wise (no progress on generalization that way...) but ultimately it's on us to make a robust benchmark. MindsAI is playing by the rules.

ARC was never supposed to grade LLMs! I designed the ARC format back when LLMs weren't a thing at all. It's a test of AI systems' ability to generalize to novel tasks.

I will never enter ARC Prize myself, since I'm organizing it. But the reason I made ARC in the first place was to work on it myself! I intend to solve it (outside of the context of the competition).

Eventually, but tax systems are usually very efficient, and feel the pain a lot later.

There is some competitive pressure with pro-business politicians wanting things to be better, but unless you're in the team seeing the problems I think they struggle to spot what could actually be improved.

This might be useful to you: if you want to have an interesting conversation, insulting your interlocutor is not the best way to go about it.

I don't think they are insulting anyone, I think they're just asking for numbers.

The history of the company does not seem to demonstrate such a semi-genius are capable of producing successful products. Can hardly be third on Cloud.

The leadership of tensorflow (which was a political football) at the time was not particularly wise, or introspective, and certainly was not interested in hearing the opinions of the large number of talented junior and senior engineers. They were trying to thread the needle of growing a large external open source project while also satisfying the internal (very advanced) needs of researchers and product teams.

This was a common pattern at the time and it's part of the reason TF 2.0 became a debacle and jax was made as a side product that matured on its own before the directors got their hands on it.

Affecting leadership's decisions at Google became gradually more difficult over time. The L8s often were quite experienced in some area, but assumed their abilities generalized (for example, storage experts trying to design network distributed strategies for HPC).

Fortunately, with the exception of a few valuable datasets and some resources, effectively everything important about machine learning has been exported from Google into the literature and open source and it remains to be seen if google will ever recover from the exodus of the highly talented but mostly ignored junior and senior engineers who made it so productive in the past.

Google in particular often downlevelled incoming engineers by one level from what their "natural" level should be- IE, a person who should have been an L6 would often be hired at L5 and then have to "prove themself" before getting that promo.

What numbers?

It’s gaslighting to make you work harder to achieve the promo.