Java Developer
Senior Kotlin/Java Backend Engineer | Kyc, Distributed Systems & Fin Tech
Hands-on Senior Backend Engineer and Technical Lead with 12+ years of software engineering experience and 10+ years building JVM systems with Kotlin, Java and Spring Boot. Kotlin has been my primary production backend language since 2023. I design and deliver event-driven, distributed backend platforms for fintech, payments, KYC/AML, customer verification and crypto transaction processing. My core stack includes Kafka, PostgreSQL, Redis, AWS and Kubernetes. I combine architecture ownership with hands-on implementation, code review, observability and production support.
Experience: 11 years
Yearly salary: $102,000
Hourly rate: $55
Nationality: 🇵🇱 Poland
Residency: 🇵🇱 Poland
Experience
Backend Architecture & Technical Leadership | Full-stack Developer
Ari10 / RGLTD 2023 - 2026
White-label fintech platform for payments, compliance, transaction orchestration and blockchain settlement. Owned backend architecture and technical direction within a 6-8-person engineering team while remaining hands-on in Kotlin, Spring Boot, PostgreSQL, Redis and AWS.
Independent Software Engineer & Technical Consultant
MG Development 2023 - 2026
Co-developed and later became the sole technical owner of a Kotlin/Spring Boot and PostgreSQL application used to prepare cryptocurrency tax settlements for hundreds of clients.
Site Reliability Engineer Team Lead
Vattenfall 2022 - 2023
Built and led the SRE/platform team, replacing single-person platform ownership with a sustainable shared-ownership model and clear engineering practices.
Software Developer
Vattenfall 2017 - 2022
Progressed from Junior to Senior-level responsibilities on a European electric-vehicle charging platform.
Software Developer Intern
Sabre Corporation 2016 - 2017
Implemented distributed tracing integration with Sabre's internal XRay platform, propagating root trace and span context across service calls and reporting telemetry for a large shared Java codebase.
Skills
architecture
aws
blockchain
crypto
docker
fintech
java
kotlin
kubernetes
kyc
microsoft
postgres
react
redis
english
polish