| name | performance-regression-debugging |
| description | Identify and debug performance regressions from code changes. Use comparison and profiling to locate what degraded performance and restore baseline metrics. |
Performance Regression Debugging
Table of Contents
Overview
Performance regressions occur when code changes degrade application performance. Detection and quick resolution are critical.
When to Use
- After deployment performance degrades
- Metrics show negative trend
- User complaints about slowness
- A/B testing shows variance
- Regular performance monitoring
Quick Start
Minimal working example:
// Before: 500ms response time
// After: 1000ms response time (2x slower = regression)
// Capture baseline metrics
const baseline = {
responseTime: 500, // ms
timeToInteractive: 2000, // ms
largestContentfulPaint: 1500, // ms
memoryUsage: 50, // MB
bundleSize: 150, // KB gzipped
};
// Monitor after change
const current = {
responseTime: 1000,
timeToInteractive: 4000,
largestContentfulPaint: 3000,
memoryUsage: 150,
bundleSize: 200,
};
// Calculate regression
const regressions = {};
for (let metric in baseline) {
const change = (current[metric] - baseline[metric]) / baseline[metric];
// ... (see reference guides for full implementation)
Reference Guides
Detailed implementations in the references/ directory:
| Guide | Contents |
|---|---|
| Detection & Measurement | Detection & Measurement |
| Root Cause Identification | Root Cause Identification |
| Fixing & Verification | Fixing & Verification |
| Prevention Measures | Prevention Measures |
Best Practices
✅ DO
- Follow established patterns and conventions
- Write clean, maintainable code
- Add appropriate documentation
- Test thoroughly before deploying
❌ DON'T
- Skip testing or validation
- Ignore error handling
- Hard-code configuration values