From my own experience and the sayings of a Friend who is lead-dev Android, developing for Android is "hair-losing": not only the platform (Android versions) ch

From my own experience and the sayings of a Friend who is lead-dev Android, developing for Android is "hair-losing": not only the platform (Android versions) change often, but there are so many different devices with so many different OSes "customized" by the manufacturers that you will spend a lot of time hunting and fixing bug. The 3 calmest languages I know are Go, Vue.JS and Rust. Go because it rarely changes, the language is simple and permits to quickly create programs with few bugs. Thanks to its big standard library, the Go ecosystem is relatively stable and there is not a lot of trendy new frameworks to learn every months. Vue.js on the frontend, like go does not change often, and is relatively opinionated which allows it to be stable and simple to learn (as opposed to react). Rust for security, embedded development and complex business logic. In contrary to Go and Vue.js it's way harder to master, and thus may fit with your expert personality. I hope it can help :)