How to diagnose performance issues in Blazor WebAssembly applications using built‑in measurement tools

When a Blazor WebAssembly app shows slow UI response, what systematic approach can be taken to pinpoint the cause using only the framework’s built‑in diagnostics and browser developer tools?

1. Enable Blazor’s built‑in performance counters by setting blazor.enablePerf=true in the app’s configuration or via query string.
2. Record a trace with the Chrome Performance panel while reproducing the slow interaction, capturing JavaScript execution, rendering, and network activity.
3. Compare the counter values (e.g., component render times, JS interop call duration) against baseline measurements from a known‑good version.
4. Identify any spikes that exceed acceptable thresholds and locate the corresponding Razor component or JS interop call.
5. Apply a targeted optimization (such as reducing render frequency or memoizing expensive calculations) and re‑run the trace to verify improvement.
6. If the change does not improve performance, roll back the modification and repeat the analysis with a different hypothesis.