Diagnostics¶

How to see, attribute, and respond to what's happening inside a running program — language-agnostic principles, with concrete examples in languages/.

Sections¶

• Debugging — interactive debuggers, post-mortem analysis, core dumps, time-travel debugging, when prints beat breakpoints.
• Logging — levels, structured logs, correlation IDs, log volume vs signal, sampling, retention.
• Error Handling — exceptions vs result types, sentinel errors, error wrapping, stack traces, recovery vs propagation.

Related¶

• Quality Engineering › Performance — when diagnostics is profiling.
• Code Craft › Clean Code › Error Handling — the source-level discipline.
• Language Internals — knowing how the runtime works makes diagnostics tractable.