Teams should include a technical test lead or other test subject matter expert who has hands-on experience with the application, rather than relying on an entry-level tester or a test project manager.

A tester or a test tool can tell you at a high level that system performance is inadequate, but finding and fixing the underlying causes falls to the developer.

For example, in the test environment, the tester or administrator might enable method-level metrics to show response times within the components of an application (or set of applications) under test.