Position: Team Lead
Category: Java
English level: upper
Years of experience: 11

* Reworked communication level solution and significantly improved performance on all levels of multitiers software solution 
* Introduced own load balancing approach which allowed company to use resources in most efficient way
* Designed and implemented high-load scalable systems from scratch.
Current duties:
Design and implementation of event driven data processing (Kafka) instead of REST approach

2021-2022 Oracle 
Development of backend services. Design and implementation of aggregation level in front of microservises level (GraphQL)

2017-2021 used to work for Chicago Boards Option Exchange (CBOE)

Development of critical server components for real-time data monitoring and delivery. Analysis and refactoring (or design and implementation new approach) of existing code to improve resources utilization and performance (network, RAM, disk, CPU). Moving data storage and data processing into the cloud.(AWS)

2015-2017 - CBOE Remote Contractor (Senior Software Developer)

Design and implementation of data structures to provide the most effective way to store and access compressed well granulated (one date + one symbol) trading data in the historical perspective. Design, implementation and support of software system to provide fast access and processing of historical data stored in the Cassandra cluster using Apache Spark.

Experience gained: practical Apache Cassandra, Apache Spark and MapReduce programming model usage. 

Before 2015 various startups + freelance