Igalia's post on self-hosting CI runners is a masterclass in build engineering. It shows dealing with weird API constraints, but still finding good designs.
I also learnt that some CI systems use OCR on Apple's installers to automate!
Today I learnt about "bypass charging", a phone feature where it can run directly off the mains without using the battery at all. No battery charging, less heat, less battery wear. Nifty.
I'm considering using WebP more: for example, my websites would load faster and browsers have supported it since 2020: https://caniuse.com/webp
That said, GitHub just added support in August 2025, so I suspect I'd still find use cases that don't work yet:
Test code is total: we require it to always terminate or it's a failure! It also typically has 100% line and branch coverage.
I feel way less nervous about refactoring tests, you can always just run them.