WhoBuilt

Nick Joseph

Head of pretraining at Anthropic

Anthropic's head of pretraining, discussing model training and infrastructure.

Key facts

Roles
Anthropic, Head of pretraining
OpenAI, Worked on a safety team and code models
Previously

Career

  1. Anthropiccurrentas of Sep 2025
    Head of pretraining
  2. OpenAIcurrent
    Worked on a safety team and code models

Timeline 4

Dated events, newest first. Open the sources under any item.

How we verify
20254 events
  1. reported 2025-09Career
    Nick Joseph is Worked on a safety team and code models at OpenAI
    “I was on one of the safety teams. I ended up working on code models.” 2:33
    Unverified1 source· Talk
    2 more roles
  2. reported 2025-09Career
    Nick Joseph previously at OpenAI
    “and then at OpenAI before Anthropic.” 0:28
    Unverified1 source· Talk

Talks 1

1:04:04
Anthropic Head of Pretraining on Scaling Laws, Compute, and the Future of AI

Nick Joseph describes how Anthropic approaches pretraining: predicting the next token across large datasets and using compute to improve model quality. He explains the engineering challenges of training at scale, from parallelizing workloads and diagnosing hardware failures to coordinating specialists across teams. He discusses how pretraining relates to reinforcement learning, post-training, alignment, and synthetic data, emphasizing that many choices need empirical testing. He also argues that inference efficiency and subtle engineering bugs will shape future progress, and that students entering AI should focus on engineering and how to make AGI beneficial.

Sep 30, 2025· 1 h 4 min 0:06
Nick Joseph, Head of pretraining at Anthropic · WhoBuilt