fix(performance): start with planning performance optimizations

readme.hints.md

@@ -318,4 +318,28 @@ const routes: IRouteConfig[] = [{
 - Authentication requires TLS termination (cannot be enforced on passthrough/direct connections)
 - Per-route connection limits are not yet implemented
 - Security is defined at the route level (route.security), not in the action
-- Route matching is based solely on match criteria; security is enforced after matching
+- Route matching is based solely on match criteria; security is enforced after matching
+
+## Performance Issues Investigation (v19.5.3+)
+
+### Critical Blocking Operations Found
+1. **Busy Wait Loop** in `ts/proxies/nftables-proxy/nftables-proxy.ts:235-238`
+   - Blocks entire event loop with `while (Date.now() < waitUntil) {}`
+   - Should use `await new Promise(resolve => setTimeout(resolve, delay))`
+
+2. **Synchronous Filesystem Operations**
+   - Certificate management uses `fs.existsSync()`, `fs.mkdirSync()`, `fs.readFileSync()`
+   - NFTables proxy uses `execSync()` for system commands
+   - Certificate store uses `ensureDirSync()`, `fileExistsSync()`, `removeManySync()`
+
+3. **Memory Leak Risks**
+   - Several `setInterval()` calls without storing references for cleanup
+   - Event listeners added without proper cleanup in error paths
+   - Missing `removeAllListeners()` calls in some connection cleanup scenarios
+
+### Performance Recommendations
+- Replace all sync filesystem operations with async alternatives
+- Fix the busy wait loop immediately (critical event loop blocker)
+- Add proper cleanup for all timers and event listeners
+- Consider worker threads for CPU-intensive operations
+- See `readme.problems.md` for detailed analysis and recommendations