web-development
DDD is not aggregates first: the discovery process is the heart of it. Why strategy with domain experts beats jumping into tactical patterns, the language pitfalls that derail modelling, the 'what if' trap, and why change must come from above and below.
architecture
Architectural Kata is a flight simulator for system design: practice big architecture decisions in a safe setting instead of waiting years for a greenfield. How a kata session works, six perspectives that change the outcome, and why architecture is communication.
ruby
AASM adds complexity most Rails apps don't need. How to replace the state machine gem with Rails 7.1+ enum, validations, and small service objects: a project management example with forms, translations, unit tests, multiple enums, and state history tracking.