Clean Craftsmanship
Uncle Bob on the three pillars of craftsmanship: TDD disciplines with examples, standards for teams, and a programmer's ethics.
Topics
refactoring 
11 posts
Improving code structure without changing its behavior.
London vs Chicago
There are two known schools in TDD: the mockist school (aka Outside-in) and the classicist school (aka Inside-out).
Test-Driven (Development)
TDD is a design practice, not just a testing technique. Writing tests first changes how you think about code and shape its structure.
Never Use array_merge in a Loop
Using array_merge inside a loop is a performance killer. The spread operator will help you to improve this by flatting the array.
Testing Effectively Legacy Code
How to write characterization tests for legacy code to safely refactor without breaking existing behavior.
Advanced Web Application Architecture
Matthias Noback on levelling up your coding and architecture: modern PHP features with a genuinely modular design.
The Art of Refactoring
If you see something, in the scope of your current task, that can be easily improved, improve it. And if you have any questions about it, ask.
Working Effectively with Legacy Code
Michael Feathers on adding tests to untested code, breaking dependencies, and refactoring legacy systems safely.
The Pragmatic Programmer
Key takeaways from Hunt and Thomas: DRY, the pragmatic mindset, and how to choose and master the tools of the trade.
Clean Code
Bad code works, but it drags a whole organization down. Uncle Bob on what clean code is and how to keep it that way.
Hands-on Refactoring and TDD
A live coding session on test-first development and refactoring, solving a code kata from scratch in pair and mob programming.