# How To Train An LLM with Anthropic's Head of Pretraining

**Author:** Y Combinator
**Type:** Video
**URL:** https://www.ycombinator.com/library/Mw-how-to-train-an-llm-with-anthropic-s-head-of-pretraining
**YouTube ID:** YFeb3yAxtjE

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Ever wonder what it actually takes to train a frontier AI model?

Ankit Gupta, YC General Partner, sits down with Nick Joseph, Anthropic's Head of Pre-training, to explore the
engineering challenges behind training Claude—from managing thousands of GPUs and debugging cursed bugs to balancing
compute between pre-training and RL. We cover scaling laws, data strategies, team composition, and why the hardest
problems in AI are often infrastructure problems, not ML problems.

