Sebastien Bourgeau

AI Research Lead, Google DeepMind · 1 appearance on the record.

computed by AI from the episodes · how this works → · full disclaimer →

scientistengineer@borgeaud_s ↗LinkedIn ↗deepmind.google ↗

Sebastian Borgeaud is an AI researcher at Google DeepMind known for co-authoring papers on RETRO retrieval and compute-optimal scaling laws. He served as a core pre-training lead for Google's Gemini models.

35statements → 13claims → 1claims resolved → 3.46/5average certainty → 2.14/5average debate potential → 4.3/5argument clarity · the sources →

1 supported 0 partly supported 0 contradicted 12 not checkable as stated how the 13 claims stand · each chip opens the sources

5 predictions · 8 assertions · 15 insights · 6 disclosures · 1 what if · every statement was checked. The predictions and assertions are the 13 claims: statements the public record can support or contradict. 1 is resolved, and 12 name no date, number or outcome precise enough to check. Everything else (opinions, insights, what ifs, disclosures) can never be settled by the record, so it carries no assessment.

The record, in short

What the tape says about how Sebastien argues and how the claims held up. Everything they said, and everything said about them, is in the tabs below.

Their most notable supported claim

Assertion Supported
Bourgeau: Thinking models compute across sequence length to test hypotheses before answering
“Rather than just doing compute in, in the depths or in, in the model side, you also do compute and allow the model to think more on, on the sequence length side of things. So the model actually starts to form hypotheses, test hypotheses, invoke some tools to v…”
Sebastien Bourgeau Dec 18, 2025 ▶ 44:07 ”We’re Ahead of Where I Thought We’d Be” — Gemini 3 & the Future of AI

Argument clarity: do they answer the question? how? →

4.3 / 5 directness 4.3 · coherence 4.8 · precision 4 · compression 3.8

answered every one of 14 assessed questions directly

This is a score against a rubric. It is not a rank. Every host question → answer exchange is scored with names hidden on directness, coherence, precision and compression, 1–5 each, on meaning alone: disfluencies are ignored, and only raw unedited episodes count. This is the score that measures thought. Every scored exchange, scores shown → · The rubric and its checks →

How they sound: speaking style how? →

244 words/min while actually speaking · 31.5 um and uh per 1k words

Measured by listening to the audio itself: 7,662 words across 1 episode of raw-level tape, transcribed verbatim with every um and uh kept, each one attributed only where the alignment onto our timed stream is unambiguous. These are measurements of speaking style. We do not rank them: across this corpus, fluency and argument quality are nearly uncorrelated (ρ≈0.2), and smooth talking does not signal clear thinking. How it's measured →

Everything Sebastien Bourgeau said on the MAD Podcast that made the record, most notable first. Filter by type, assessment or year in the ledger →

Assertion Not checkable as stated
Bourgeau: AI progress from pre-training improvements is not slowing down
“It's still remarkable how much progress we're able to achieve in this way, and it's not really slowing down.”
Sebastien Bourgeau Dec 18, 2025 ▶ 2:26 ”We’re Ahead of Where I Thought We’d Be” — Gemini 3 & the Future of AI
Assertion Not checkable as stated
Bourgeau: Google and DeepMind are actively researching post-Transformer architectures
“I believe so. There's groups doing research on the model architecture side, for sure, within Google and within DeepMind”
Sebastien Bourgeau Dec 18, 2025 ▶ 10:38 ”We’re Ahead of Where I Thought We’d Be” — Gemini 3 & the Future of AI
Insight
Bourgeau: Architecture and data innovation currently matter more than scale
“The other parts are architecture and data innovation. These also play a really, really important part in the Performance of pre-training and probably even more so than pure scale these days, but scaling is still an important factor as well.”
Sebastien Bourgeau Dec 18, 2025 ▶ 31:22 ”We’re Ahead of Where I Thought We’d Be” — Gemini 3 & the Future of AI
Assertion Not checkable as stated
Bourgeau: AI development is not running out of training data
“The other part of your question are we running out of data? I don't think so, so there's more.”
Sebastien Bourgeau Dec 18, 2025 ▶ 34:15 ”We’re Ahead of Where I Thought We’d Be” — Gemini 3 & the Future of AI
Insight
Bourgeau: AI research is shifting to a data-limited paradigm
“I think what might be happening instead is kind of a shift in paradigm where before we were kind of scaling in the data unlimited regime where, where data would scale as much as you would like. And we're kind of shifting more to a data limited regime, which ac…”
Sebastien Bourgeau Dec 18, 2025 ▶ 34:26 ”We’re Ahead of Where I Thought We’d Be” — Gemini 3 & the Future of AI
Prediction Not checkable as stated
Bourgeau: End-to-end differentiable retrieval and search in training will take years
“I think deep down, I do believe that the long-term answer is to learn this differentiable end-to-end way, which means probably doing pre-training or whatever that looks like in the future, Learn to retrieve as part of the training and learn how to do search as…”
Sebastien Bourgeau Dec 18, 2025 ▶ 40:09 ”We’re Ahead of Where I Thought We’d Be” — Gemini 3 & the Future of AI
Insight
Bourgeau: AI models must be trained on harmful data to avoid it
“So at a fundamental level, you did, you do need the model to know about those things. So you have to train a bit at least on those so that it knows what those things are and knows to stay away from those, right?”
Sebastien Bourgeau Dec 18, 2025 ▶ 43:14 ”We’re Ahead of Where I Thought We’d Be” — Gemini 3 & the Future of AI
Prediction Not checkable as stated
Bourgeau: Retrieval-augmented pre-training could become viable in a few years
“I just think it's not unreasonable to think in the next few years, something like that might actually become viable for a leading model like general.”
Sebastien Bourgeau Dec 18, 2025 ▶ 50:54 ”We’re Ahead of Where I Thought We’d Be” — Gemini 3 & the Future of AI
Insight
Bourgeau: Gemini 3 progress came from small contributions, not one breakthrough
“In my experience, there's maybe one or two of those things that make a larger difference than other things, but it's really a combination of many, many changes and many, many things from a very large team that actually makes Gemini three so much better than th…”
Sebastien Bourgeau Dec 18, 2025 ▶ 1:45 ”We’re Ahead of Where I Thought We’d Be” — Gemini 3 & the Future of AI
Insight
Bourgeau: Frontier AI development is about building systems, not just neural networks
“We're not really building a model anymore. I think we're really building a system at this point. People have sometimes this view that we're just training a neural network architecture and that's it. But it's really the entire system around the network as well …”
Sebastien Bourgeau Dec 18, 2025 ▶ 2:46 ”We’re Ahead of Where I Thought We’d Be” — Gemini 3 & the Future of AI
Disclosure
DeepMind's Bourgeau: AI progress is ahead of where I expected
“I think, if I'm being honest with myself, I think we're ahead of where I thought we could go.”
Sebastien Bourgeau Dec 18, 2025 ▶ 5:00 ”We’re Ahead of Where I Thought We’d Be” — Gemini 3 & the Future of AI
Assertion Not checkable as stated
Bourgeau: Gemini 3's architecture hasn't changed much from Gemini 2.5
“At the high level, I don't think the architecture has changed that much compared to the previous one. It's more of what I was saying before, where a few different things come together to gather, give a large, large improvement.”
Sebastien Bourgeau Dec 18, 2025 ▶ 26:52 ”We’re Ahead of Where I Thought We’d Be” — Gemini 3 & the Future of AI
Assertion Not checkable as stated
Bourgeau: Gemini answers computer science benchmark questions taking humans significant time
“They are becoming increasingly difficult, and even for me, who has a background in computer science, some of the questions the model answers, it would take me a significant amount of time to answer.”
Sebastien Bourgeau Dec 18, 2025 ▶ 3:41 ”We’re Ahead of Where I Thought We’d Be” — Gemini 3 & the Future of AI
What-if
Bourgeau: Would not have bet heavily on scaling laws materializing
“I, I'm not sure if I would have bet a lot on, on that actually materializing and being where we are today.”
Sebastien Bourgeau Dec 18, 2025 ▶ 5:26 ”We’re Ahead of Where I Thought We’d Be” — Gemini 3 & the Future of AI
Prediction Not checkable as stated
DeepMind's Bourgeau predicts major AI-driven scientific breakthroughs within years
“I think we will be able to make some large scientific discoveries in the next few years.”
Sebastien Bourgeau Dec 18, 2025 ▶ 6:14 ”We’re Ahead of Where I Thought We’d Be” — Gemini 3 & the Future of AI
Prediction Not checkable as stated
Bourgeau: Agentic workflows will accelerate AI research tasks in the next year
“The first part, I think, especially in the next year with more agentic workflows being enabled more and more, that should be able to really accelerate our work there.”
Sebastien Bourgeau Dec 18, 2025 ▶ 7:35 ”We’re Ahead of Where I Thought We’d Be” — Gemini 3 & the Future of AI
Insight
Bourgeau: AI scale has blurred the line between research and engineering
“I think over time that boundary has blurred quite a lot because we're working on these very large systems now. Research really looks like engineering and vice versa.”
Sebastien Bourgeau Dec 18, 2025 ▶ 11:28 ”We’re Ahead of Where I Thought We’d Be” — Gemini 3 & the Future of AI
Disclosure
Bourgeau: DeepMind shifted focus from pure research to research engineering
“And I think that's a mindset that has really evolved over the last few years at DeepMind, especially where maybe there was a bit more of the traditional research mindset before, and now with Gemini, it's really more about research engineering.”
Sebastien Bourgeau Dec 18, 2025 ▶ 11:38 ”We’re Ahead of Where I Thought We’d Be” — Gemini 3 & the Future of AI
Disclosure
Bourgeau works with 150 to 200 people on Gemini pre-training
“So it's a fairly large team at this point. It's a bit hard to quantify exactly, but maybe a 152 hundred people I work on a day-to-day on the pre-training side between data, model, infrastructure, evals, and so coordinating the work of all of these people into …”
Sebastien Bourgeau Dec 18, 2025 ▶ 12:52 ”We’re Ahead of Where I Thought We’d Be” — Gemini 3 & the Future of AI
Assertion Not checkable as stated
Bourgeau: Early DeepMind research defaulted to synthetic data over real-world data
“And at the time we had to add this from real world data to the name of the project, because people would assume otherwise it would be synthetic environments or synthetic data. And that definitely has shifted completely since then.”
Sebastien Bourgeau Dec 18, 2025 ▶ 17:34 ”We’re Ahead of Where I Thought We’d Be” — Gemini 3 & the Future of AI
Insight
Bourgeau: Trading peak model performance for lower complexity enables faster progress
“Oftentimes we don't necessarily want to use the best performance version of a research idea, but we'd rather trade off some of the performance for a slightly lower complexity version because we think that will allow us to do more and more progress in the futur…”
Sebastien Bourgeau Dec 18, 2025 ▶ 21:35 ”We’re Ahead of Where I Thought We’d Be” — Gemini 3 & the Future of AI
Insight
Bourgeau: In deep learning, negative results often mean unoptimized techniques
“Especially in deep learning, a negative results doesn't mean something doesn't work. It means you haven't made it work yet often.”
Sebastien Bourgeau Dec 18, 2025 ▶ 22:48 ”We’re Ahead of Where I Thought We’d Be” — Gemini 3 & the Future of AI
Disclosure
Bourgeau: Google leadership's research background shields DeepMind from benchmark pressure
“There's actually very little of that. I think because all of the leadership has a research background that they're very much aware that yes, to some extent you can force and accelerate specific benchmarks and certain goals, but in the end, the progress and the…”
Sebastien Bourgeau Dec 18, 2025 ▶ 25:12 ”We’re Ahead of Where I Thought We’d Be” — Gemini 3 & the Future of AI
Insight
Bourgeau: Pre-training scaling lessons apply directly to RL scaling
“On the RL and RL scaling side, I think we're seeing a lot of the same things we're seeing in pre-training or we saw in pre-training. What's interesting here is because we have the experience of pre-training, a lot of the lessons apply, and we can reapply some …”
Sebastien Bourgeau Dec 18, 2025 ▶ 32:24 ”We’re Ahead of Where I Thought We’d Be” — Gemini 3 & the Future of AI

Show 11statements(11 left)

Appearances (1)

EpisodeDateSpeaking time
”We’re Ahead of Where I Thought We’d Be” — Gemini 3 & the Future of AI Dec 18, 2025 36m
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