optimize

# Performance optimizer Analyze and suggest performance improvements for code, queries, or systems. ## Purpose Identify optimization opportunities: - Runtime performance bottlenecks - Memory usage issues - Database query inefficiencies - Bundle size problems - Algorithm complexity ## Instructions ### Step 1: Scope identification Determine optimization target: - **Function**: Single function performance - **Module**: Related functions/classes - **Query**: Database query optimization - **Bundle**: Frontend bundle analysis - **System**: Architecture-level optimization ### Step 2: Performance analysis #### Runtime analysis ```bash # Find potentially slow patterns grep -rn "forEach\|\.map\|\.filter\|\.reduce" --include="*.{ts,js}" . | head -20 # Find nested loops (O(n²) potential) grep -rn "for.*for\|\.forEach.*\.forEach\|\.map.*\.map" --include="*.{ts,js}" . | head -10 # Find sync operations that could be async grep -rn "readFileSync\|writeFileSync\|execSync" --include="*.{ts,js}" . | head -10 ``` #### Memory analysis ```bash # Large array operations grep -rn "new Array\|Array\.from\|\.concat\|spread" --include="*.{ts,js}" . | head -10 # Potential memory leaks (event listeners, intervals) grep -rn "addEventListener\|setInterval\|setTimeout" --include="*.{ts,js}" . | head -10 ``` #### Database query analysis ```bash # N+1 query patterns grep -rn "await.*find\|await.*query" --include="*.{ts,js}" . | head -15 # Missing indexes hints grep -rn "WHERE\|ORDER BY\|GROUP BY" --include="*.{ts,js,sql}" . | head -15 ``` #### Bundle analysis ```bash # Check bundle size (if applicable) [ -f "package.json" ] && npm run build 2>/dev/null && ls -lh dist/*.js 2>/dev/null # Large dependencies [ -f "package.json" ] && cat package.json | jq '.dependencies | keys[]' | head -20 ``` ### Step 3: Prioritization Rank findings by: 1. **Impact**: How much will this improve performance? 2. **Effort**: How hard is the fix? 3. **Risk**: What could break? ## Output format --- ### ⚡ Performance analysis **Target**: [file/module/system] **Analysis Date**: [timestamp] ### 📊 Current Metrics (if measurable) | Metric | Current | Target | Gap | |--------|---------|--------|-----| | Response time | Xms | <Yms | -Z% needed | | Memory usage | XMB | <YMB | -Z% needed | | Bundle size | XKB | <YKB | -Z% needed | ### 🔴 Critical issues #### 1. [Issue title] - [location] **Problem**: [What's slow and why] **Current**: ```typescript // O(n²) - nested loops users.forEach(user => { permissions.forEach(perm => { if (user.id === perm.userId) { ... } }); }); ``` **Optimized**: ```typescript // O(n) - Map lookup const permMap = new Map(permissions.map(p => [p.userId, p])); users.forEach(user => { const perm = permMap.get(user.id); if (perm) { ... } }); ``` **Impact**: ~10x faster for 1000 users **Effort**: Low (5 min) **Risk**: Low ### 🟠 High priority | Issue | Location | Impact | Effort | |-------|----------|--------|--------| | [description] | file:line | [estimate] | [time] | ### 🟡 Medium priority | Issue | Location | Impact | Effort | |-------|----------|--------|--------| | [description] | file:line | [estimate] | [time] | ### 💡 Quick wins 1. [Small change with good impact] 2. [Another quick optimization] 3. [Low-hanging fruit] ### 📈 Optimization roadmap ``` Week 1: Critical fixes (items 1-3) Week 2: High priority (items 4-6) Week 3: Measure and validate improvements ``` --- ## Common patterns ### Array operations | Pattern | Issue | Fix | |---------|-------|-----| | `arr.filter().map()` | Two iterations | Single `reduce()` or `flatMap()` | | `arr.find()` in loop | O(n²) | Build Map/Set first | | `[...arr1, ...arr2]` | Memory allocation | `arr1.concat(arr2)` or push | ### Database | Pattern | Issue | Fix | |---------|-------|-----| | Loop with await | N+1 queries | Batch query with `IN` | | `SELECT *` | Over-fetching | Select only needed columns | | Missing WHERE index | Full table scan | Add composite index | ### React/frontend | Pattern | Issue | Fix | |---------|-------|-----| | Inline functions in JSX | Re-renders | `useCallback` | | Large list rendering | DOM thrashing | Virtualization | | Unoptimized images | Slow LCP | Next/Image, lazy loading | ### Node.js | Pattern | Issue | Fix | |---------|-------|-----| | Sync file operations | Blocks event loop | Async alternatives | | JSON.parse large files | Memory spike | Streaming parser | | No connection pooling | Connection overhead | Pool with pg-pool, etc. | ## Usage **Analyze specific file:** ``` /optimize src/services/user.ts ``` **Focus on specific area:** ``` /optimize --queries src/repositories/ /optimize --bundle /optimize --memory src/workers/ ``` **With target metrics:** ``` /optimize --target=100ms src/api/search.ts ``` **Quick scan:** ``` /optimize --quick ``` ## Notes - Measurements beat assumptions: profile before optimizing - Premature optimization is the root of all evil (Knuth) - Focus on hot paths: optimize what runs often - Consider trade-offs: speed vs readability vs maintainability $ARGUMENTS