If your iOS background tasks aren't firing and you're not sure why, this is the debugging guide you need. It walks you through BGTaskScheduler mechanics, the seven scheduling factors iOS uses to decide when your code runs, and a systematic checklist for the "registered but never executes" problem every iOS dev hits eventually. The docs are clear that background execution is discretionary, not guaranteed, which is the right framing. Covers iOS 13+ with BGTaskScheduler and iOS 26+ continued processing tasks. It's focused purely on making tasks run and complete correctly, not on energy optimization, which lives in a separate axiom-energy skill.
npx skills add https://github.com/charleswiltgen/axiom --skill axiom-background-processing