What tools and approaches do you use to identify and fix errors in the application's business logic?

To identify and fix errors in the application's business logic, I use several tools and approaches:

• Logging: I add detailed logs at key points in the code to track the flow and variable values.
• Debugger: I step through the code to check the state of variables and understand where the error occurs.
• Unit tests and integration tests: I write tests that cover the business logic to quickly identify regressions and errors.
• Code review: Collaborative code review helps find logical errors and improve quality.
• Requirements and use case analysis: I verify that the implementation meets the business requirements.

Example: if the total order amount is calculated incorrectly in the application, I first add logs to the calculation function, then run the debugger to check intermediate values, and write tests with different input data to ensure correct operation.