Posts to read for fun, like taking everything apart over a coffee to see what's inside, down to the deepest bolt. Come away understanding more, judging more clearly and deciding with a steadier hand.
The Gang of Four's 23 patterns were written for C++ and Smalltalk. In Python, Strategy is a function, Singleton is a module, Iterator is a generator. A tour of the patterns still used every day, found in real code, with how many nanoseconds each kind of indirection costs.
The five SOLID principles aren't laws; they're ways to keep one change from bringing down the whole system. Each comes with a runnable example: a square that breaks a rectangle, dict.get skipping __getitem__, and tests with fakes almost 2,000 times faster than a database.
Code is now read, changed and extended by people and AI agents alike. Tidying a 26-line pricing function step by step: a test over 20,000 random orders first, then names, no magic numbers, no nested ifs, smaller functions, measured complexity, and how agents find, read and imitate code.