• Android SDK: Services, Fragments, Concurrency, GCM, Location and Sensor APIs, Custom UI, Camera API, SQLite, ContentProvider, Preferences, Maps API, Animation, Drive SDK, TextToSpeach, Media, Webview (+JS), Google Play Services, Firebase Services, Transitions API, Retrofit, RxJava / RxAndroid, Stream API, LiveData, Room, ViewModel, MVVM, Kotlin
• Java EE: Jersey, Glassfish
• .NET: C# Windows Forms
• SQL: MySQL, SQLite, PostgreSQL
• CVS: Git, Mercurial, Tfs
• Operation Systems: Linux, Windows
• Other: Clean Architecture, Design Patterns, REST, Gradle, Redmine, Material Design