Refactoring improves the design of code in many ways. Refactoring improves the design of code by taking a bad design and making it a good one and making the code easier to work with.

By testing your code during the refactoring process allows you to make your code more readable and also more functional. Testing during the refactoring process also allows you find and remove duplicate code fragments.

Modularisation. It could also be called refactoring, where large and complex functions are split into several simpler functions, making code easier to read. Refactoring can also help to reduce code duplication.

I analyze the code to understand their logic and functionality. Comparing it with the desired outcome or requirements, I identify any errors or areas for improvement. By debugging or refactoring the code, I aim to optimize its performance and adherence to best practices.

Irum Iqbal Godil has written:

'An open infrastructure for refactoring aspects'