Qualcomm camera HAL flow ■ Linux device driver ■ Linux HW probe flow (ex:dtsi) ■ camera and sub-module bring up ■ basic Android app experience ■ OOP 2. Android App ■ HTTP Connection to Web API ■ Jsoup(web crawler) ■ XML Parser ■ Android API SQLite DataBase by CRUD ■ GPS ■ AIDL Inter process communication ■ ContentProvider ■ Fragment ■ RxJava ■ Retrofit ■ OkHttp ■ Volley 3. Programming language ■ Java ■ C/C++ ■ Shell Script 4. Version Control ■ git ■ gitk 5. IDE ■ Android