Code Review & Test Time Compute — Tips from Boris Cherny
A summary of insights shared by Boris Cherny (@bcherny), creator of Claude Code, on March 10, 2026.
1/ Introducing Code Review
New in Claude Code: Code Review. A team of agents runs a deep review on every PR.
- Built for Anthropic's own team first — code output per engineer is up 200% this year, and reviews were the bottleneck
- Boris has been using it for a few weeks and found it catches many real bugs he would not have noticed otherwise
- When a PR opens, Claude dispatches a team of agents to hunt for bugs
Why Code Review?
Code output per engineer is up 200% this year, and reviews were the bottleneck. Claude Code Review dispatches a team of agents to hunt for bugs on every PR.
2/ Test Time Compute & Multiple Context Windows
Roughly, the more tokens you throw at a coding problem, the better the result. Boris calls this test time compute.
- Using separate context windows makes the result even better — this is what makes subagents work, and why one agent can cause bugs and another (using the same exact model) can find them
- Similar to engineering teams: if Boris causes a bug, his coworker reviewing the code might find it more reliably than he can
- In the limit, agents will probably write perfect bug-free code — until then, multiple uncorrelated context windows tends to be a good approach
Key Insight
Using separate context windows makes the result even better. One agent can cause bugs and another (using the same exact model) can find them — just like how a coworker reviewing your code catches bugs you missed.