neutral

// ArjanCodes
Avoiding the Refactoring Trap: Lessons in Logic and Specification
When refactoring messy business logic, 'cleaner' code often masks dangerous behavioral changes. Discover why your unit tests might show 86% coverage while still missing critical logic errors that break your production environment. We explore the transition to a specification pattern and the hidden traps of assuming you've truly understood legacy requirements.
3 min read
// ArjanCodes
Writing Resilient Python Unit Tests: Beyond the Basics
Unit testing external APIs often feels like a chore of manual overrides and brittle code. By shifting from messy monkey patching to clean dependency injection and pytest fixtures, you can transform your test suite from a burden into a powerful design tool. Explore how to isolate logic effectively and ensure your production code remains bulletproof.
4 min read

last updated Jan 2, 2026