# AI coding agents speed up writing but slow down reviews

> Study finds pull‑request review time jumps 49% after firms add AI coding assistants, while code‑review workload rises.

Oossa · 2026-10-09 · https://oossa.com/en/ai-coding-agents-speed-up-writing-but-slow-down-reviews

Researchers looked at firms that added AI coding agents. The time between a pull request’s submission and its merge grew by 49 percent. Pull requests also needed changes twice as often, and comments per request rose 35 percent. About 14 percent more workers started doing code reviews, but overall staffing levels stayed flat. By March 2026, 80 percent of firms used AI for some review comments, yet the agents produced only 23.3 percent of those comments.

## The facts

- Review time rose 49 % after AI agents were introduced
- Share of pull requests with changes requested nearly doubled

## Why it matters

Software teams may see faster code generation but must budget extra time for human reviews.

## Sources & references

1. [AI coding agents generate more code, but not more software](https://arstechnica.com/ai/2026/10/ai-coding-agents-generate-more-code-but-not-more-software/) – Ars Technica, 2026-10-09
2. [Code Understanding is a Bottleneck for Coding Agents](https://www.microsoft.com/en-us/research/publication/code-understanding-is-a-bottleneck-for-coding-agents/) – Microsoft Research Publications

Last updated: 2026-10-09