In which context should callouts be placed in test classes to ensure proper execution?

Callouts should be placed between Test.startTest() and Test.stopTest() in test classes to ensure proper execution because this is the designated area where asynchronous processes, such as HTTP callouts, can be executed in a simulated testing environment.

The Test.startTest() method signals the start of the test context, allowing for resource limits to be reset and transactions to be governed. This means that any callouts made after this method will be accounted for in the test's context and will not interfere with any governor limits. Placing callouts after Test.stopTest() would be irrelevant because at that point, the test execution is completed, and the results are finalized.

Similarly, while callouts can be executed within test methods, they need to be positioned correctly within the start and stop boundaries to ensure they function as intended without hitting limits or returning unexpected results. Placing callouts before starting the test would not include them in the test context, thus failing to properly validate their behavior within the framework of the test.