Definition: Code-level performance testing measures the performance of individual functions or methods while the code is being written. It looks at response times at function or method level and checks for problems such as memory leaks, often using profiling or probe tools for the language in use.
So what? Many performance problems are cheaper to fix in the code than after integration, when they may need architectural changes. Testing at code level starts performance work as soon as development begins.
Examples: Profiling a new method during development to find an unexpectedly slow database call. A performance tester suggesting good performance practices to developers at the start of a sprint.
