The same events that print a tree or fill a file can feed an OpenTelemetry backend while the application runs, with one trace id shared across files, headers and spans.

One endpoint is slow and there are three layers it could be. Self time for the handful of methods you chose answers the question without a profiler and without a stopwatch in every layer.

One HTTP request as one tree, from a single config entry, with the failing request saying both that it answered 500 and why.

Tracing an application you cannot or should not edit: the bindings and sink move into a TOML file next to the project, and the program runs untouched.

The bindings used to test a piece of code are the same objects that trace it. Take away the timeline, register a sink, and a running program narrates itself.

What a wrapture binding can name that is not a call: attribute reads and writes, values held in place for a test, the content of a settings dict, callables in a registry, and generators consumed...