Java Developer

OPTIVEUM sp. z o.o.; Warszawa; Hybrid; PLN 180,000 - 240,000; Full time

Job summary

A US-based technology firm is seeking a skilled Java Developer to join their backend engineering team in Warsaw. This role involves designing and maintaining scalable services and APIs, with an emphasis on collaboration and innovation. Requirements include strong Java proficiency, experience with Spring, and a minimum of 4 years in backend development. This position offers remote work transitioning to hybrid, a competitive salary up to $6,500, and a full benefits package.

Benefits

Competitive salary up to 6,500 USD

Full benefits package

Generous paid time off

Learning opportunities

Qualifications

• Strong proficiency in Java (Java 11+).
• 4+ years of professional experience in backend development.
• Experience with Spring Boot / Spring Cloud.

Responsibilities

• Design and maintain server-side services in Java.
• Build RESTful APIs and possibly GraphQL.
• Optimize existing systems and troubleshoot production issues.

Skills

Java proficiency

Spring Boot

Object-oriented design

RESTful APIs

Debugging skills

Agile/Scrum

Education

Bachelor’s or Master’s degree in Computer Science

Tools

PostgreSQL

Message queues (e.g. Kafka)

CI/CD tools (e.g. Git)

Job description

Java Developer

Location: Warsaw / Hybrid (initially remote, moving to hybrid ~3 days/week on-site)

Company: US-based technology firm in private capital / financial markets

Employment Type: Full-time

About the Role

We are looking for a skilled Java Developer to join our backend engineering team. You will help build and maintain high-performance, scalable, distributed systems and APIs that handle core business workflows and data processing in a mission-critical domain. You’ll work closely with frontend engineers, product, QA, and operations to deliver robust, secure, and maintainable solutions.

Key Responsibilities

• Design, implement, and maintain server-side services and microservices in Java (Spring, Jakarta EE, etc.)
• Define and build RESTful APIs, possibly GraphQL, and other backend interfaces
• Architect and develop scalable solutions, emphasizing performance, reliability, fault tolerance, and high availability
• Integrate with databases (relational, NoSQL), message queues, and third-party services
• Participate in code reviews, technical design discussions, and architecture planning
• Write clear, maintainable, and well-tested code (unit / integration / end-to-end tests)
• Troubleshoot and resolve production issues (monitoring, logging, diagnostics)
• Optimize existing systems, refactor modules, and drive continuous improvement
• Stay current with Java ecosystem trends, frameworks, tools, and best practices

What We’re Looking For (Required)

• Strong proficiency in Java (Java 11+, or whichever version your stack uses)
• Experience with Spring Boot / Spring Cloud (or equivalent Java frameworks)
• Solid understanding of object-oriented design, design patterns, clean architecture
• Experience building RESTful APIs, and (ideally) GraphQL or event-driven APIs
• Familiarity with relational databases (PostgreSQL, MySQL, Oracle) and/or NoSQL (e.g. MongoDB, Redis)
• Experience with message queues / streaming systems (e.g. Kafka, RabbitMQ)
• Experience with unit testing, integration testing frameworks (JUnit, Mockito, etc.)
• Working knowledge of CI/CD pipelines, version control (Git), and DevOps practices
• Strong debugging skills, performance tuning, and production issue analysis
• Ability to work in an Agile / Scrum environment

Nice to Have (Preferred / Bonus)

• Experience in microservices architecture, domain-driven design, event sourcing, CQRS
• Familiarity with cloud platforms (AWS, Azure, GCP) — e.g., deploying Java services, serverless, containers (Docker, Kubernetes)
• Experience with other JVM languages (Kotlin, Scala)
• Exposure to GraphQL, gRPC, or WebSockets
• Knowledge of security standards, OAuth2 / OpenID Connect, JWT
• Experience in the financial / capital markets / fintech domain
• Experience with distributed caching, caching strategies
• Experience with observability tooling (Prometheus, Grafana, ELK / EFK stack)

Qualifications / Experience

• Bachelor’s or Master’s degree in Computer Science, Software Engineering, or related technical discipline
• 4+ years (or adjust accordingly) of professional experience in backend development with Java
• Demonstrated track record of designing and delivering reliable backend systems

What We Offer

• Competitive salary up to 6 500 USD
• Remote start, transitioning to hybrid (Warsaw)
• Full benefits package
• Generous paid time off
• Opportunity to work on impactful, financial / capital market systems
• Collaborative, innovative, and tech-driven culture
• Learning opportunities, conferences, trainings, etc.