Agentic coding is straining CI. Here’s how we scaled test impact analysis at Anthropic

Anthropic engineers on average ship 8x as much code per quarter as they did from 2021-2025. Claude authors 80% of that code and it also plays a large role in reviewing and approving PRs as well. On top of that, the amount of tests across our codebase grew 10x and we added a nominal amount of engineers. This all led to a 25x increase in CI jobs over a six month period (in case you are trying to do the math, not every test runs on every PR as I will explain).

Published by Claude Blog. This page is a short excerpt; the full text is theirs.