It's pretty common to have quick unit tests so you can cycle thru TDD without having to recompile the world and start-up/reload the application. You can get a few hours of work done with TDD without ever opening the actual application.
In legacy enterprise, you're rarely doing green field work. You usually spend time reading coding and planning a safe edit. When you do change a line and have to recompile the world, its common to actively read and plan your next change while waiting.
It's pretty common to have quick unit tests so you can cycle thru TDD without having to recompile the world and start-up/reload the application. You can get a few hours of work done with TDD without ever opening the actual application. In legacy enterprise, you're rarely doing green field work. You usually spend time reading coding and planning a safe edit. When you do change a line and have to recompile the world, its common to actively read and plan your next change while waiting.