How can I measure and diagnose performance bottlenecks in a Blazor Server application?

Developers building Blazor Server apps often notice slower UI updates under load but lack a systematic way to pinpoint whether the delay originates from component rendering, SignalR circuit latency, or JavaScript interop. The goal is to establish a repeatable measurement process that isolates each layer while respecting constraints such as production‑like traffic, minimal instrumentation overhead, and compatibility with existing diagnostic tools.

Without clear baselines, it is unclear which metrics—frame‑time, round‑trip time, or render‑queue length—best indicate a bottleneck, and how to correlate them across client and server sides. Which lightweight profiling approaches can capture per‑component render times without affecting SignalR throughput? How can server‑side circuit latency be measured alongside client‑side JavaScript interop calls? What thresholds for metrics like DOM update latency or SignalR round‑trip time reliably indicate a performance issue in Blazor Server?