GitHub only
Fix a slow API endpoint
Devin benchmarks a slow dashboard endpoint, profiles it, fixes the causes, and reports p50, p95 and p99 latency before and after.
Steps
- Enter your GitHub user or org. The links and the prompt on this page use it.
- Create your own copy of the starter repo. Open GitHub's new-repository page for devin-demo-performance, choose your account as the owner, keep the name
devin-demo-performance, and click Create repository. - Make sure Devin can access the new repo under Settings → Connections → GitHub.
- Start a session at app.devin.ai and paste the prompt below.
Prompt
Customers say the dashboard in https://github.com/<you>/devin-demo-performance is painfully slow. Make it fast, with proof.
Seed the realistic dataset (`npm run seed`) and measure the baseline with the repo's benchmark (`npm run bench`, report p50/p95/p99). Profile to find where the time actually goes (show the evidence: query counts, timings, a flamegraph or --cpu-prof output). Fix the root causes without changing response shape (existing tests must pass, add one that guards against regression). Re-run the identical benchmark and open a PR with a before/after table of p50/p95/p99 and RPS plus what you changed and why.What to watch
- It measures a baseline before changing anything.
- The fix is backed by profiler evidence, not hunches.
You're done when
- The PR has a before/after table of p50, p95, p99 and RPS.
- Existing tests pass, plus a new one that guards against regression.