Former OpenAI researcher Weijia Shi joins Anthropic for pretraining

Former OpenAI researcher Weijia Shi announced on Sept 19 that she had joined Anthropic the previous month to work on pretraining, expressing excitement about the work ahead. Multiple peers congratulated her, confirming the move.

Confirmed

• Weijia Shi herself announced joining Anthropic last month for pretraining work
• According to Ziqiao Ma, she previously worked on o1-related research at OpenAI and is known for LongRoPE and sycophancy work
• Researchers including Ziqiao Ma and billyuchenlin forwarded congratulations

Why it matters

• This is another notable talent flow between OpenAI and Anthropic, two frontier labs
• Her o1-era research experience strengthens Anthropic's pretraining team, a core lever for frontier model capability

2026-09-19 ~ 2026-09-20 · 8 related posts

• [source] Researcher Weijia Shi Joins Anthropic to Work on Pretraining — WeijiaShi2 · 2026-09-19
• Researcher Weijia Shi joins Anthropic to work on pretraining — billyuchenlin · 2026-09-19
• [source] Researcher Weijia Shi Joins Anthropic to Work on Pretraining — ziqiao_ma · 2026-09-20

5 near-duplicate retellings: StellaLisy · mrdrozdov · jmin__cho · kohjingyu · lasha_nlp