4.3s to under 3s mobile load. The sequence:
- Remove 3 unused apps (~600ms)
- Defer non-critical JS (~300ms)
- WebP images with explicit dimensions (~250ms + CLS)
- Preconnect hints (~150ms)
- Schema markup cleanup (~100ms)
- Remove unused CSS (~80ms)
~1 week of focused work. Lesson: instrument, fix in priority order, measure after each change.