How to Refactor Insanely Complicated Business Logic (Step by Step)

In this monologue podcast, Arjan demonstrates how to refactor complex code, specifically a function with multiple nested if-else statements. He emphasizes the importance of understanding the existing code and capturing its behavior through tests before making changes. Arjan then outlines a step-by-step approach, which includes flattening the code structure using guard clauses, simplifying and naming conditions, merging duplicate code, removing unnecessary try-except blocks, simplifying loops, and using data structures to represent stable rules. He illustrates these techniques by refactoring a Python function that approves orders based on user type, order details, and region, ultimately transforming it into a more readable, testable, and maintainable piece of code.