tuyv Performance Knowledge
Knowledge base. No runtime actions; authoring conventions for maintainers below. Read the relevant references/*.md files directly via the Read tool.
Two entry points
- Diagnosing an existing regression →
references/diagnose-table.md(symptom → bucket). - Reviewing a proposed change before merge →
references/review-checklist.md(diff pattern → rules to load).
Cross-cutting anti-patterns
These look right but aren't. Check every review or diagnose pass against this table.
| Looks like… | Actually… |
|---|---|
Adding CDN-Cache-Control to fix TTFB |
Netlify strips them; CF ignores due to max-age=0. |
Using unstable_cache in MDX routes |
Triggers ISR → runtime 404s. See edge-caching.md. |
await import(`.../${locale}/${ns}.json`) |
Webpack enumerates all combinations → OOM. Use fs.readFile. |
Adding a useSession / cookies() in root layout |
Every route becomes dynamic. Edge caching dies silently. |
priority: true via getImageProps() on manual <picture> |
fetchPriority attribute is not set; add it manually. |
Bumping revalidate to hourly to "fix staleness" |
Increases edge miss rate. Keep daily; add client /api/* for freshness. |
| Mocking DB/content in perf tests | Perf wins must be measured against real prod build (pnpm build && start). |
Removing common.json keys without audit |
Lookups of removed keys silently render the bare key (fallback). Grep the key across src/ and app/ first. |
File map
| Topic | File |
|---|---|
| Symptom → bucket routing | references/diagnose-table.md |
| Diff pattern → rules routing | references/review-checklist.md |
| TTFB, edge caching, CDN | references/edge-caching.md |
| Bundle size, code splitting, RSC payload | references/bundle.md |
| Build OOM, ENOSPC, file tracing | references/build.md |
| INP, main-thread work | references/inp.md |
| LCP, images | references/images.md |
For data-fetching patterns (Trigger.dev tasks, Netlify Blobs, src/lib/data caching, internal /api/* routes, fetcher retries), use the data-layer skill instead.
Conventions for adding rules
- One topic per file; no content duplication across files.
- Cite a PR (
PR #N) when a rule comes from a specific shipped change. Add a SHA only when no PR exists. - Forward-looking ("do this, avoid that"). Keep entries prescriptive — no postmortems or incident narratives.
- New review check? Add a row to
review-checklist.mdAND the matching bucket file. Don't restate the rule inline.