Profiling JavaScript Like A Pro
summary
Browser rendering runs at 60fps (≈16ms per frame) with ~5–6ms browser overhead leaving ~10ms of work; the pixel pipeline is JavaScript → style → layout → paint → composite and a reflow runs the whole pipeline while a repaint skips layout. Profiling with Chrome DevTools Performance and Memory tabs plus the performance monitor finds hotspots (example: a costly decimalToHex routine uses 31% and 1.7s, changed to CSS rgb and removed console.log drops load to 158ms), change detection to onPush change detection cuts 100ms components to 0.2ms, heap snapshots and allocation timelines (and node --inspect / heapdump, autocon load testing) locate leaks like a duplicated 20MB object fixed by a single shared service.
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chapters (13)
- 0:00Introduction to profiling
- 1:50Browser rendering pipeline
- 8:33RAIL performance model
- 10:41Chrome DevTools profiling
- 17:29Profiling workflow steps
- 25:04Memory leaks overview
- 27:59How memory allocation works
- 31:32Garbage collection algorithms
- 34:05JavaScript memory leak pitfalls
- 35:10Detecting memory leaks in browser
- 42:42Node.js memory leak detection
- 48:31Production monitoring tips
- 49:36Q&A session
