Notes from building Castria — mobile architecture, audio, and teaching an app to hear an ad.
Castria finds the ads in a podcast episode and skips them. Transcribing the episode is what makes that expensive, and until now I've paid that bill for everyone. Castria 2.0 changes it: you pay in compute or you pay in money, and either way everyone listening to that show gets the result.
Castria is a podcast app that automatically detects and skips ads — no manual scrubbing, no sitting through the same 90-second read every episode. It runs today on iOS, Android, and the web from one shared codebase. Getting there took two rewrites. The second one, forced by Android, taught me more…