· System administration Corporate and trunk networkingNetwork equipment Operation systems Windows, LinuxVoIP TechnologyMS ADDC Virtualization (VMWare, Hyper-V)Cloud services (Amazon AWS, DigitalOcean, AlibabaCloud)· DevOpsDockerGit (Gitlab, Github)Deploy CI\DIMessaging System (NATS)Unit-test· Programming languages.NET C#Go (Golang);Objective-C Java (SE, JavaFX, for Desktop Application)Android ApplicationJavaScript (ReactJS, VueJS)Other script interpreters (Bash, Powershell, Perl, LUA)· DataBaseSQLiteMSSQLMySQLPostgreSQLBoltdbMongoDBRedisGoogle Firebase· Other directions of development:Develop for IoT and Embeded devices (SoC, RaspberryPi, Arduino)Data exchange technologies XML/JSON, gRPCMicro services architecture RESTfull, RPC (JSON), JWT, WebSocket,Telegram bot development … Keep learning every day