Quicktip: Cut CI time with deterministic dependency cache keys

If your pipeline spends most of its time reinstalling dependencies, cache them deterministically with your lockfile hash so cache hits are safe and repeatable.

Suggested pattern

1. Keep npm ci as the installer to guarantee lockfile fidelity.
2. Configure cache key with:
   • OS
   • package manager
   • lockfile hash
3. Add restore keys for same OS + manager fallback.

Why this works

• You get fast cache hits when dependencies are unchanged.
• Any lockfile change naturally invalidates stale cache.
• Build behavior remains reproducible across branches.

This usually drops install time by 30-70% in medium-size repos.