Devin use cases: 14 real examples

Within one night Devin produced a working unanswered-emails interface using the Gmail API, after the author wrote the authentication code themselves.

Small scoped fixes took about five minutes to test and merge versus roughly an hour by hand; the full-stack task failed and was rewritten.

After 2-3 review rounds the PR was production-ready and merged. The task took about 1 hour versus roughly 15 minutes coding it alone.

Devin found nearly every old term in a docs-wide rename, but the edits still needed 20+ manual commits.

A working, deployed app that shows images, weather, and news for a city, finished in roughly 90 minutes from an empty repo.

Cognition merged 659 Devin PRs into its own codebase in one week, up from 154 in its best week of 2025.

Cognition merged 659 Devin-authored PRs into its own codebase in one week, up from 154 in its best week of 2025.

Devin built a three-endpoint Express API in about 4 minutes, but chose the wrong pagination style on a real codebase and needed review and refactoring.

Test runs approved per day on Devin more than doubled in a couple of months, and engineers run 10 to 20 Devins in parallel.

The unfinished output is work the author would have quoted at about €2.5k, built in one overnight run.

Users resolved issues by talking to Devin, engineers only merged when needed, and Devin Review caught bugs.

Out of 20 tasks, Devin had 14 failures, 3 successes, and 3 inconclusive results, with no pattern predicting which would work.

Out of 20 tasks, Devin had 14 failures, 3 successes, and 3 inconclusive results, with no predictable pattern for which would work.

Devin opened a PR in about four hours and got the build passing, but runtime issues remained and the author gave up.