In an industry obsessed with the latest frameworks, Arjan codes breaks down why the 'how' of coding is secondary to the 'why' of software design. From the performance leaps of Python 3.11 to the hidden dangers of over-engineering with design patterns, this deep-dive explores the transition from junior coder to senior architect. Learn why data integrity tests are more vital than unit tests for mission-critical systems and how brain science can actually make you a more efficient programmer.