• September 7, 2026

  5 design patterns used in my new habit tracker app

  There are plenty of habit trackers, but I wanted to build mine with constraints, a calendar view and habit streaks. So I built commitgraph: a small Django + HTMX app. Here are five Python design and testing patterns from building it.

• June 19, 2026

  End-to-End Testing Every Rust Exercise with Playwright

  The Rust platform has 71 exercises and counting (I just added a new track of Unix exercises). They all share the same interface: load an editor, type code, validate it against a Rust backend. When I make any changes to the platform, how do I confirm nothing breaks? Enter end-to-end testing with Playwright.

• June 3, 2026

  How to Tell if Your Python Mock Is Actually Working

  A test can pass for the wrong reason. When you're mocking a third-party API call, the test might look green because the real API happened to return an error, not because your mock did anything at all.