Sergey Sitnikov is a founding engineer based in Serbia with about 15 years of hands-on software development spanning system-level C, Java/Eclipse platform work, and high-load backend systems. He is an EMF-based modeling and Eclipse/SWT expert who has built and redesigned numerous editors—implementing features like code completion, documentation and formatting for the ECL language—and modernized Q7’s UI and SWT instrumentation for more predictable development iterations. Sergey contributes to notable open-source projects such as Hazelcast and OrientDB, focusing on indexing, query performance and core transaction/record-store fixes, and has produced Hazelcast code samples that demonstrate advanced indexing techniques. He also authored a widely used freeware Windows utility, VisualTaskTips, with over 1.5 million downloads, and favors parsing, online large-data stream processing and probabilistic algorithms, combining deep internals knowledge with pragmatic production engineering and mentoring.
9 years of coding experience
24 years of employment as a software developer
Bachelor's degree, Computer Science, Bachelor's degree, Computer Science at Siberian State University of Telecommunications and Information Sciences
Hazelcast is a unified real-time data platform combining stream processing with a fast data store, allowing customers to act instantly on data-in-motion for real-time insights.
Role in this project:
Back-end Developer
Contributions:156 reviews, 205 commits, 285 PRs in 5 years
Contributions summary:Sergey primarily contributed to improving the Hazelcast backend by fixing bugs and adding features. They addressed missing calls to superclasses, enhanced Javadocs for the IMap interface to clarify value vs reference semantics, and fixed a typo. Their work included modifications to the core codebase, specifically within the query and record store packages to address index and performance issues related to compactions.
OrientDB is the most versatile DBMS supporting Graph, Document, Reactive, Full-Text and Geospatial models in one Multi-Model product. OrientDB can run distributed (Multi-Master), supports SQL, ACID Transactions, Full-Text indexing and Reactive Queries.
Role in this project:
Back-end & Database Engineer
Contributions:269 commits, 39 PRs, 284 pushes in 1 year 6 months
Contributions summary:Sergey contributed to the OrientDB codebase, which is a multi-model DBMS. They were involved in deprecating untyped indexes and addressing transaction propagation issues, particularly concerning auto-started and user-initiated transactions. The commits demonstrate involvement in core database functionality and transaction management within the graph database features.
dbmsrdbmsindexingrelational-databasesreactive
Find and Hire Top DevelopersWe’ve analyzed the programming source code of over 60 million software developers on GitHub and scored them by 50,000 skills. Sign-up on Prog,AI to search for software developers.