Profiling
35 bites tagged Profiling — interview questions with model answers, and 60-second explainers.
React Native's Performance Monitor Overlay
Think of it as a quick, in-app speedometer for your app's performance. Toggle it from the Dev Menu for a live overview on your screen. The footgun: it's only a guide, not a precise tool for deep performance analysis.
Node.js perf_hooks: A High-Precision Stopwatch for Your App
The `perf_hooks` module is a high-precision stopwatch for your Node.js code, offering nanosecond accuracy. Use it to benchmark async operations or HTTP request durations.
Xcode's Time Profiler: Hunting Down Performance Bottlenecks
Time Profiler is a stopwatch for your code, sampling your app's threads to see which functions are running most often. Use it to diagnose slow UI or high battery drain by finding CPU "hot spots."
Go Execution Tracer: Pinpointing Concurrency Bottlenecks
Go's Execution Tracer creates a visual timeline of your program, capturing goroutine state changes, syscalls, and GC events. It's essential for diagnosing subtle concurrency issues like lock contention. The main footgun is misusing annotations for work.
Go Memory Profiling with pprof
pprof takes a snapshot of your Go app's memory usage, showing which functions allocate the most. Use it to diagnose high memory consumption or find leaks. A common footgun is profiling total allocations (`allocs`) instead of current memory use (`heap`).
Go's pprof: Finding Your Code's Hotspots
pprof is a heat map for your code, revealing which functions consume the most CPU. It samples your program's call stacks to find performance hotspots. Use it to diagnose slow API endpoints or high-CPU background jobs. The footgun: profiling under no load.
Performance Profiling in Tests
Performance profiling in tests means capturing frame build and raster times during a scripted, automated run instead of eyeballing smoothness, so jank regressions get caught in CI before they ever reach a real device.
Find Jank with Flutter's CPU Flame Charts
A flame chart visualizes CPU usage, showing which function calls are slowest. Use it to diagnose jank in Flutter. The footgun is misreading the x-axis: it's for sorting calls alphabetically, not showing execution order.
Profiling Flutter Apps with Dart DevTools
Dart DevTools is your app's diagnostic tool, letting you see exactly why frames drop or memory spikes. Use it to find the root cause of "jank" in lists or slow animations.
Perfetto: See Your Whole System on One Timeline
Perfetto is a flight recorder for your system, capturing kernel and app events on a single timeline. Use it to diagnose complex issues like jank by correlating app behavior with system activity.
Android Studio Profiler: Find Your App's Bottlenecks
The Android Studio Profiler is your app's diagnostic dashboard, showing real-time CPU, memory, and network usage. Use it to hunt down UI jank, find memory leaks, and optimize battery-draining network calls.
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