Sergey Chernolyas
Expert Java Developer at Digital Future Group
Belgrade, Central Serbia
Summary
👤
Senior🎓
Top SchoolSergey Chernolyas is an expert Java developer with two decades of software engineering experience and over a decade in senior and lead roles delivering high-performance, distributed systems. He has led greenfield microservices and event-driven architectures, optimizing throughput (3x improvements) and building resilient patterns such as idempotent, out-of-order event handling with NATS, ShedLock, and Keycloak security integration. Sergey brings strong fintech and regulated-environment experience—implementing GDPR cross-service flows across 15 microservices—and hands-on work with Kafka, Flink, Docker, Kubernetes and modern Java (Java 21). An active open-source contributor, he has improved testing and MongoDB/native query support in notable projects like Hibernate OGM and strengthened test automation in the Alluxio data orchestration project. Based in Belgrade, he combines deep backend craftsmanship with pragmatic leadership and a proven ability to refactor legacy systems into scalable, testable platforms.
11 years of coding experience
14 years of employment as a software developer
Master's degree, Computer Science, Master's degree, Computer Science at Novocherkasskiy Gosudarstvenniy Tehnicheckiy Universitet
English, Russian
Stackoverflow
1reputation
35reached
0answers
1question
Github Skills (23)
unit-testing10
testing10
alluxio10
java10
mongodb-database10
javas10
junit10
hibernate10
mongodb10
query-optimization9
orchestrate9
orchestration9
hazelcast6
data-analysis5
api-rest4
Programming languages (6)
Github contributions (5)
hibernate/hibernate-ogm
Apr 2016 - Dec 2017
Hibernate OGM - Domain model persistence for NoSQL datastores
Role in this project:
Back-end Developer
Back-end DeveloperContributions:14 commits, 68 PRs, 255 comments in 1 year 7 months
Contributions summary:Sergey primarily contributed to the back-end aspects of the Hibernate OGM project. Their work included writing unit tests for utility classes, migrating to the MongoDB Java Driver 3.x API, and refactoring code. The user also added support for new operations such as `replaceOne`, `updateOne`, `updateMany`, `deleteOne`, and `deleteMany` to enable more advanced MongoDB native query functionality within the OGM framework. These changes enhance the data store's capabilities for handling various database operations.
domain-modeljdbcormmongodbdatabase
Alluxio/alluxio
Oct 2016 - Nov 2016
Alluxio, data orchestration for analytics and machine learning in the cloud
Role in this project:Back-end Developer & QA Engineer/Test Automation Engineer
Back-end Developer & QA Engineer/Test Automation EngineerContributions:35 commits, 12 PRs, 57 comments in 1 month
Contributions summary:Sergey primarily focused on improving the test suite for the Alluxio project. Their contributions include adding and utilizing the ExpectedException Rule for more robust testing and modifying existing test classes to account for version compatibility and correct test setup. The user also introduced new test cases for the AlluxioMasterRestServiceHandler, demonstrating a focus on testing server-side functionalities. The user is also responsible for refactoring code and implementing several unit tests.
data-analysisvirtual-distributed-filesystemanalyticsorchestrationdata-science
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