Development and support of the billing system (C #, MSSQL, REDIS, IIS, NGINX, Linux, Windows Server) more than 7 years. Ensuring mutual settlements between mobile operators, their partners and copyright holders. The billing system is vertically and horizontally scalable, fault tolerant and is calculated by 10 million events per day.Managing IT department to create new projects from scratch on request. For example, the program counting program of deer, statistics on the femto-cells of the operator, etc.Working in the company that installed and made windows and was the leader in this industry (the state of more than 900 people in the company). The number of dealer offices is about 70 pcs. Development of programs for a dealer Company departments sihronizatsiya data with the plant. Development of programs for machine control (via COM port)