What it is
A command-line tracer that uses Intel Processor Trace to continuously record every branch a running process takes into a circular buffer, then saves a snapshot on Ctrl+C or when a chosen function is called. The resulting trace opens in a web viewer as a zoomable timeline of call stacks with roughly 40ns resolution and low overhead, with no changes to the application. Systems and performance engineers use it to find slow requests in production, see what code actually did before a crash, and inspect behavior that sampling profilers like perf miss. It runs on Linux with Intel Skylake or newer CPUs.
