AI-Generated Code Is Already Competing With Human Code — Daksh Gupta, Greptile

More than a quarter of the pull requests Greptile reviewed in April showed signs of being written largely or entirely by AI agents, up from under 1% a year earlier. Daksh Gupta, co-founder of Greptile, analyzed more than a million pull requests a month from companies like NVIDIA, Coinbase and Scale to test a simple question: are fully vibe-coded PRs actually any good in enterprise codebases? He compares agent-written PRs (Codex, Claude Code, Devin, Cursor) with human-written ones on four measures: revert rates, revert rates by PR size, the severity of issues Greptile flags (P0/P1/P2), and how many review rounds it takes to get to a mergeable PR. On all four, agent code landed in the same range as human code, and humans were actually more likely to introduce P0 bugs. The differences show up in *how* each one fails: Claude is about 1.5x more likely than humans to introduce SQL injection, Devin is half as likely to cause auth bypasses, and N+1 queries are far more common from Cursor. Daksh also shares what this means for code review. The median Greptile user makes fewer than 50 commits a month, while the 99th percentile makes close to 1,000, which makes manual review impossible at that scale. He argues that code validation should answer three questions: Does this change violate the user contract? Does it make a future violation more likely? Does it do what the author intended? He then shows how Greptile answers them with blast-radius analysis and sandboxed browser agents that try to break the app. Speaker info: - Greptile: https://greptile.com - Daksh Gupta on X: https://x.com/dakshgup - Daksh Gupta on LinkedIn: https://www.linkedin.com/in/dakshg/ - Daksh's website: https://dakshgupta.com Timestamps: 00:00 Intro 00:25 Daksh Gupta & Greptile 00:57 From tab complete to fully autonomous agents 02:09 Are fully vibe-coded PRs any good? 02:29 How to detect vibe-coded PRs: author fields, co-author footers, branch prefixes 03:49 25%+ of PRs vibe coded, up from under 1% a year ago 04:18 What makes a pull request "good"? 04:38 Revert rates: Codex vs. Devin vs. humans 05:28 Do revert rates change with PR size? 06:08 Severity of issues found: P0s, P1s and P2s 07:02 Review rounds to reach a mergeable PR 07:47 Different failure modes: SQL injection, auth bypass, N+1 queries 09:07 Autonomous agents work in enterprise settings 10:01 What this means for code review: 50 vs. 1,000 commits a month 10:51 Rethinking code validation: three questions 11:16 How Greptile validates: blast radius + sandboxed browser agents 11:56 Closing