If you love this operation system, you'll be in heaven.
We work in Kotlin, but we just need you to know Java and we can teach you the rest. We are used to working with Retrofit, Room, Databinding, and more.
You should also be familiar with project architecture, in this case we work on the Android platform according to MVVM, but the basics of working with Git or SVN would come in handy as well.
You will definitely work with reactive programming and REST. You get extra points if you have basic experience with data persistence ... And that's all.
Does not sound too hardcore, does it? If you enjoy our approach, definitely get in touch and we can develop the next app together.