Open to opportunities

Oleh Kulbaba

@olehkulbaba

Message

I build reliable payment microservices with Java, Spring Boot, Kafka, and AWS.

Ukraine

Message

What I'm looking for

I'm looking to build and own reliable backend services, especially payment and event-driven systems, while growing through complex technical work, peer reviews, and collaborative delivery.

At PrivatBank, I build payment-processing microservices with Java 21, Spring Boot, Apache Kafka, PostgreSQL, MongoDB, and Redis. I improved authentication token handling with distributed locks, implemented reliable outbox-style Kafka publishing, migrated about 10 services to Spring Boot 4, and built an SLA monitoring service end to end.

Previously at Chewy, I developed payment transaction hydration and asynchronous retry flows using AWS SQS, automated EKS deployments with Helm, restored distributed request traceability, and created integration tests and technical documentation for a scalable payment platform.

Experience

Work history, roles, and key accomplishments

Current

Software Engineer

Current

PrivatBank

Jan 2025 - Present (1 year 7 months)

Developed payment features across Java 21 / Spring Boot microservices, implemented authentication with distributed locking, made Kafka event publishing reliable using an outbox pattern, migrated ~10 microservices from Spring Boot 3 to 4, and designed an SLA monitoring service end to end.