Lex Fridman, Sebastian Raschka, and Nathan Lambert survey the 2026 state of AI: LLMs, scaling, open models, China, agents, and AGI.

Sebastian Raschka and Nathan Lambert — Sebastian Raschka is a machine learning researcher and author of 'Build a Large Language Model from Scratch' and 'Build a Reasoning Model from Scratch.' Nathan Lambert is the post-training lead at the Allen Institute for AI (Ai2) and author of a definitive book on Reinforcement Learning from Human Feedback.
In this multi-guest roundtable, Lex Fridman talks with researchers Sebastian Raschka and Nathan Lambert about the state of AI roughly a year after the 'DeepSeek moment.' They debate who is winning between US and Chinese labs, dissect the explosion of open-weight models, and explain the technical lineage from GPT-2 to today's architectures (Mixture of Experts, attention variants, KV cache). A large portion covers training stages, scaling laws, and the rise of reinforcement learning with verifiable rewards (RLVR) and inference-time scaling. They also discuss education and learning, careers in AI, tool use, continual learning, robotics, timelines to AGI/ASI, the business and consolidation landscape, NVIDIA's moat, and Nathan's ADAM Project to build American open models.
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Sebastian Raschka
“Sebastian is the author of two books I highly recommend for beginners and experts alike. First is Build a Large Language Model from Scratch” — Lex Fridman 00:00:31Find it on Amazon
Sebastian Raschka
“two books I highly recommend for beginners and experts alike. First is Build a Large Language Model from Scratch and Build a Reasoning Model from Scratch” — Lex Fridman 00:00:31Find it on Amazon
Nathan Lambert
“Nathan is the post-training lead at the Allen Institute for AI, author of the definitive book on Reinforcement Learning from Human Feedback” — Lex Fridman 00:01:01Find it on Amazon
David Talbot (inferred)
“It's a great book, Season of the Witch. I recommend it. A bunch of my SF friends who get out recommended it to me.” — Nathan Lambert 02:28:01Find it on Amazon
Anthropic
“You can select the same models on all of them and ask questions, and it's very interesting. Claude Code is way better in that domain. It's remarkable.” — Lex Fridman 02:23:36Find it on Amazon
Anysphere (inferred)
“I should say I use Composer a lot because one of the benefits it has is that it's fast.” — Lex Fridman 03:39:17Find it on Amazon
xAI
“I actually do use Grok 4 Heavy for debugging. For like hardcore debugging that the other ones can't solve, I find that it's the best at.” — Sebastian Raschka 00:17:39Find it on Amazon