Hands-on experience in developing and maintaining MMORPG game servers (similar to RuneScape). Developed and maintained game server logic for an MMORPG, including combat system, player interactions, raids and minigames mechanics. Used built-in database for storing NPC and items data, also edited various files responsible for saving data. Ensured server stability and performance for hundreds/thousands of concurrent players. Worked with Java and Spring Framework. Developed API (receive a response about voting wins, automatically send codes to Discord, automatically add and remove giveaway videos to games, register a player's email address, and send messages to it.) Used multithreading Collaborated with a designer and implemented interface design into the code.

Worked as developer of financial and accounting program database system modules. I have experience with JavaScript for frontend part and with MUMPS for backend. Developed and maintained database routines using MUMPS. Worked with hierarchical data structures and optimized queries for performance. I created visual presentations of modules for users of Ukrainian universities using JavaScript, HTML and CSS.