I'm currently working as a Technical Team Lead, but I can also work as Android or Backend Developer (depending on what the project needs). My favorite topics are highly scalable application architecture and performance (both for mobile and backend projects).
I'm working mainly in Kotlin (when talking about mobile projects), but I also love C# as a tooling/backend language. I'm familiar with Rust just enough to not be scared of it and to know how the backbone of higher-level technologies work. I love getting deep into how the languages and runtimes work.