Open to opportunities

OGnev User

@ognevuser

Java backend engineer specializing in scalable FinTech systems and event-driven microservices with Kafka and Spring Boot.

Russian Federation

Message

What I'm looking for

Open to remote opportunities and international teams. I want backend engineering challenges focused on scalable Java/Spring services, Kafka-driven event systems, and real-time, production-reliable architectures.

I’m a Java Backend Engineer with 4+ years of experience building production-grade backend systems in FinTech and enterprise software environments. I focus on scalable backend services, event-driven architectures, distributed systems, and real-time applications using Java and the Spring ecosystem.

At VeloStrana, I owned ChatService and AuditService within a microservice architecture supporting 4,000 employees and handling 800–1,000 peak RPS. I designed real-time delivery with SSE and Apache Kafka, improved performance by reducing MongoDB load via Redis caching, and fixed production race conditions by introducing timestamp-based event ordering in Kafka consumers. I also implemented Kafka Fan-Out routing, built Kafka-driven audit/notification pipelines, and added security monitoring for IDOR brute-force attempts.

Previously at PromTransBank, I developed backend services for a corporate internet banking platform and improved account statement query performance by 20x (6–7 seconds to 200–300 ms). I fixed a critical double-payment race condition with request idempotency and database-level uniqueness, reduced Hibernate N+1 queries down to 2–3 using JOIN FETCH/EntityGraph/DTO projections, and increased automated test coverage from 40% to 70% with JUnit and Mockito.

Experience

Work history, roles, and key accomplishments

Middle Java Developer

VeloStrana

Feb 2024 - Mar 2026 (2 years 1 month)

Owned ChatService and AuditService in a microservice architecture supporting ~4,000 employees and 800–1,000 peak RPS. Built real-time messaging using SSE and Kafka, reduced MongoDB load via Redis caching, and resolved production race conditions by applying timestamp-based Kafka event ordering.

Middle Java Developer

VeloStrana (Retail Tech Company, Internal Messaging Platform for 4,000

Feb 2024 - Mar 2026 (2 years 1 month)

- Owned ChatService and AuditService within a microservice architecture supporting 4,000 employees and handling 800–1,000 peak RPS.

- Designed real-time message delivery using Server-Sent Events (SSE) and Apache Kafka, enabling low-latency communication across horizontally scaled service instances.

- Reduced MongoDB load and eliminated redundant reads by migrating hot-path data to Redis, sig

Java Developer

PromTransBank

Mar 2022 - Dec 2023 (1 year 9 months)

Developed backend services for a corporate internet banking platform for legal entities. Improved account statement query performance by 20x using PostgreSQL indexing/query optimization, fixed a double-payment race condition using request idempotency and database uniqueness, and reduced Hibernate query count by resolving N+1 issues.

Java PostgreSQL Spring Data Spring Cloud Redis Git Spring Boot Spring Framework Java Development Hibernate Spring MVC Kafka Docker Query Optimization N+1 Query Optimization Correlation IDs

Java Developer

PromTransBank (FinTech, Digital Banking for Legal Entities)

Mar 2022 - Dec 2023 (1 year 9 months)

- Developed backend services for a corporate internet banking platform serving legal entities.

- Improved account statement query performance by 20x (from 6–7 seconds to 200–300 ms) through PostgreSQL indexing and query optimization.

- Fixed a critical double-payment race condition by implementing request idempotency and database-level uniqueness guarantees.

- Reduced Hibernate query count f