Developed backend of the Exchange. Maintain real-time statistics data structures for traders, such as candles, order books. Build REST and WebSocket API over them.

Custom development for internal clients in Avito. Developed, implemented, and maintained a distributed data processing system with 300m online enriched events per day. Built API for 1,3 trillion documents Elastic cluster. Built API for reading Kafka topic with 150k/s events. Built a reporting system. Migrating hundreds of Parquet TB from Vertica to Elastic.

Backend Java Developer Worked on afisha.yandex.ru backend. Worked on event schedule import and aggregation for whole Russia and neighbors. Worked on REST, GraphQL gRPC, SOAP API for events, orders, sessions, and so on with 1k RPS. Worked on integration with a hundred partners. Worked on order reserve and payment processing. Worked on CMS making users happier. Refactored. Conducted code reviews. -Designed and implemented a subscription feature with thousands of users. -Designed and implemented an algorithm that increased movie purchase conversion by 10%. -Designed and implemented a shopping cart feature with 30 write RPS. -Participated in establishing the coding and unit-testing standards in my team. -Proposed and introduced a code analysis tool used in the team to increase code quality and reduce bugs. -Proposed and introduced a tool to keep documentation actual. -Designed and implemented a multithreaded sitemap crawler to keep links working.