Source code has two aspects of quality, namely functional and structural. The functional quality of a piece of source code can be achieved by testing the code against the customer specifications. The biggest mistake most developers make is that they tend to commit the code to version control software without refactoring it; that is, they commit the code the moment they believe it is functionally complete.
As a matter of fact, committing code to version control often is a good habit, as this is what makes continuous integration and DevOps possible. After committing the code to version control, what the vast majority of developers ignore is refactoring it. It is highly critical that you refactor the code to ensure it is clean, without which being agile is impossible.
Code that looks like noodles (spaghetti) requires more efforts to enhance or maintain. Hence, responding to a customer's request quickly is not practically possible. This is why maintaining clean code is critical to...