I've been able to supercharge a hobby project of mine over the last couple months using Opus 4.6 in claude code. I had to collaborate and write code still, but claude did like 75% of the work to add meaningful new features to an iOS/Android native mobile app, including Live Activities which is so overly complicated i would not have been able to figure that out. I have it running in a folder that contains both my back end api (express) and my mobile app (nativescript), so it does back end and front end work simultaneously to support new features. this wasnt possible 8 months ago.