09/20/2026 updated
not available
info: not available until 01/01/2027
Senior Java Engineer | Microservices | Spring Boot | Kafka | DDD
Szczecin, Poland
Germany +5
MSc Computer Science, BSc Automatic Control & Robotics – West Pomeranian University of Technologyinfo: Germany, Austria, Switzerland, United Kingdom, Netherlands, Poland
About me
Java engineer from Szczecin, Poland, working remotely for a Norwegian client since 2021 through my own company. I like clean architecture, good tests and meeting the teams I work with, so I combine remote work with regular on-site visits. I write about my microservices project: jrobertgardzinski.pl
Java (Programming Language)Behavior-Driven DevelopmentElasticsearchSpring FrameworkJUnitPostgreSQLSoftware ArchitectureMockitoTypeScriptSpring CloudReact.jsSpring BootBackendEvent Driven ArchitectureApache Kafka
Java & Spring Boot Development
9 years in software development, 7 of them with Java (versions 8 through 21) and Spring / Spring Boot, covering backend, full-stack and QA work. Production work with Elasticsearch, PostgreSQL and NATS JetStream; Kafka in a near-duplicate detection system and in my own portfolio; Quarkus in one service.
Microservices & Software Architecture
Design and implementation of loosely-coupled, event-driven microservices systems applying Domain-Driven Design and Hexagonal Architecture. Saga-orchestrated workflows over Kafka in my portfolio project (described on my blog) and contract-driven integration (JSON Schema) between services written in different languages.
Testing & Quality Assurance
Rigorous testing practice using JUnit 5, Mockito, Cucumber BDD, ArchUnit and property-based testing with jqwik. Experience with E2E and regression test automation, as well as contract and integration tests against real messaging and storage infrastructure (NATS, MinIO).
Cloud & DevOps
Docker and docker-compose for containerisation and local environment setup. Release engineering across a large monorepo; builds run in Jenkins. Observability stack with Prometheus, Grafana, Loki and Tempo. Azure storage and S3-compatible object storage with MinIO.
Security & Authentication
Platform authentication based on OAuth2 / OpenID Connect (Keycloak). CORS/CSP hardening, dependency and CVE management, and securing browser-to-desktop-service integration.
AI-Assisted Engineering
Disciplined use of AI-assisted development tools such as Claude Code for implementation, refactoring and test generation, with transparent AI co-authorship in commits. Containerised Model Context Protocol (MCP) servers and built MCP tooling for platform data.
Frontend Technologies
Practical experience with React, Redux, TypeScript, Angular and GWT. Delivered full-stack features spanning REST backends and React frontends, including notifications, chat and licensing subsystems.
Data Streaming & Messaging
NATS JetStream in a production data pipeline (deduplication and sink stages, verified by contract, BDD and end-to-end tests). Apache Kafka for a near-duplicate detection system (orchestrator plus pluggable algorithm workers, dead-letter queues, idempotent completion) and for the saga in my portfolio.
Database Technologies
Experience with PostgreSQL, MongoDB and Elasticsearch for relational, document and search use cases respectively, each used as dedicated datastores in microservices architectures.
Embedded & Legacy Systems
Earlier experience with C# / .NET, SignalR and C++, including microcontroller debugger scripting using PRACTICE / Lauterbach TRACE32 and semi-automated regression testing for embedded ship-controller modules.
Experience
Professional experience5 - 10 years
Freelancer since2019
Languages
EnglishFluentPolishNative speaker
Project history
Remote software development for a Norwegian oil and gas data sector client. Responsibilities included platform maintenance and tooling (sole maintainer of a desktop-integration service in Java/Spring Boot), AI-assisted engineering (containerising MCP servers, designing near-duplicate document detection systems), data pipeline and test engineering (deduplication and sink stages, metadata validation, E2E test automation with Cucumber and Playwright), and product features (notifications subsystem, in-platform chat, video player, licensing subsystem). Stack: Java 8-21, Spring Boot, Quarkus, Kafka, NATS JetStream, Elasticsearch, PostgreSQL, MongoDB, GWT, React, Docker.
Developer on a GDPR policy-management platform using Spring and Angular. Worked directly with the Product Owner on requirements and code changes. Delivered pandemic-era projects on tight deadlines including a component of the Polski Bon Turystyczny programme and a rental system. Implemented authentication security with brute-force protection and CAPTCHA integration.
Contributed to an automotive data-collection system gathering measurement data from vehicle test drives for an emissions-compliance programme, coordinated directly with a German customer in English. Participated in on-site live testing in Stuttgart. Built a terminal-based chat application over sockets in C++ with unit tests. Stack: C#, SignalR, C++, HTML, JS.