maggit Performance Analyzer
Identify and resolve performance bottlenecks.
Workflow
Understand the problem:
- What is slow? (startup, specific endpoint, rendering, query, build)
- What are the symptoms? (high latency, high CPU, high memory, timeouts)
- What is the target? (e.g., "under 200ms", "half the memory")
Profile before optimizing:
- Identify the hotspot. Never optimize blindly.
- Use language-appropriate profiling:
- Python:
cProfile,py-spy,memory_profiler,time.perf_counter - Node.js:
--prof,clinic.js,console.time,perf_hooks - Go:
pprof,go test -bench - Rust:
cargo bench,flamegraph - General:
timecommand,hyperfinefor benchmarks
- Python:
Analyze the code for common issues:
Common Performance Issues
| Category | What to look for |
|---|---|
| Algorithm | O(n^2) or worse where O(n log n) exists, unnecessary sorting |
| Database | N+1 queries, missing indexes, SELECT *, no pagination |
| I/O | Sequential where parallel is possible, no batching, no streaming |
| Memory | Large object copies, no generators/iterators, memory leaks, unbounded caches |
| Caching | Repeated expensive computations, no memoization, cache stampede |
| Rendering | Unnecessary re-renders, large DOM, no virtualization |
| Network | No compression, no connection pooling, chatty APIs |
| Build | No tree-shaking, large bundles, no code splitting |
Propose fixes ranked by impact:
- Estimate improvement for each fix.
- Start with the highest-impact, lowest-effort changes.
- Include before/after benchmarks when possible.
Verify improvements:
- Run benchmarks before and after.
- Check for regressions in correctness.
- Monitor for changes in memory usage.
Guidelines
- Measure first, optimize second. Show numbers.
- The biggest gains are usually algorithmic, not micro-optimizations.
- Consider trade-offs: readability vs speed, memory vs CPU, latency vs throughput.
- Don't optimize code that runs rarely — focus on hot paths.
- Suggest caching strategies where appropriate but warn about invalidation complexity.
- For database issues, show the query plan (
EXPLAIN ANALYZE).