Senior Java Back-end developer

Worldline; Warszawa; Hybrid; PLN 180,000 - 300,000; Full time

Benefits offered by this job

Private medical & life insurance

Public transportation allowance

Annual bonus

Job summary

Worldline is hiring for a Risk Technology Services Engineer in Warsaw. You will work on architecture, APIs, and cloud delivery while owning end-to-end delivery of features. You’ll mentor peers and shape technical direction in a hands-on, collaborative team.

You’ll contribute to CI/CD pipelines, containerized services, and robust observability, with a focus on secure, reliable production systems.

Qualifications

• 4+ years of professional Java development experience.
• Experience with modern Java (latest LTS) and current language features.
• Proficiency in Java OOP and functional programming principles.
• Strong Spring Boot experience including Spring Security/OAuth2.
• Relational DB experience (PostgreSQL), schema design and query optimization.
• Experience with Flyway or Liquibase migrations.
• Designing RESTful APIs and integrating distributed services.
• Experience with Docker and CI/CD (Jenkins, GitLab CI).
• Unit and integration testing (JUnit, Testcontainers).
• Software architecture knowledge (clean/hexagonal, DDD).
• Secure coding, resilience, and observability in production.

Responsibilities

• Collaborate across teams to deliver new features and services; set standards and technical direction for Risktech service.
• Own architecture and design decisions: service boundaries, APIs, data models, and contracts.
• Design database schemas and manage migrations across versions.
• Design and build RESTful APIs and event-driven integrations between services.
• Apply resilience patterns and champion test-driven development with strong coverage.
• Own delivery: contribute to CI/CD pipelines, containerization, cloud infra and observability.
• Diagnose complex issues across services and infrastructure; lead incident resolution.
• Code reviews and mentoring for mid-level and junior developers.
• Establish and uphold coding standards, security practices, and design principles.

Skills

Java development

Spring Boot

REST APIs

CI/CD pipelines

Docker

SQL & PostgreSQL

Unit testing

Software architecture

Git

Security & observability

Tools

Flyway

Liquibase

Jenkins

GitLab CI

JUnit

Testcontainers

PostgreSQL

Job description

Worldline helps businesses of all shapes and sizes to accelerate their growth journey - quickly, simply, and securely. We are the innovators at the heart of the payments technology industry, shaping how the world pays and gets paid. Our technology powers the growth of millions of businesses across 5 continents. And just as we help our customers accelerate their business, we are committed to helping our people accelerate their careers. Together, we shape the evolution.

The opportunity

As a member of the Risk Technology Services technical team, you'll go beyond writing high-quality code–youwillengage actively in architectural discussions, contribute to technical decisions, and take genuine end-to-end ownership of what you ship. From service design and API development to cloud infrastructure and delivery pipelines, you'll bring strong engineering fundamentals and a platform mindset to a team that builds and operates software together. We're looking for someone who is hands-on, collaborative, and makes the people around them better simply by doing great work.

Day-to-day responsibilities

Work closelywithacrossfunctionalteamon thedelivery of new features and services;settingthestandardandtechnical direction forRisktech service.

Own architecture and design decisions: service boundaries, APIs, cross-service contracts, and data models-balancing simplicity, reliability, security, and maintainability.

Design database schemas and manage evolution through versioned migrations.

Design and buildRESTful APIsand asynchronous/event-driven integrations between services.

Apply resilience patterns (retries, idempotency, circuit breakers) and champion test-driven development with strong coverage.

Own delivery: contribute to CI/CD pipelines, containerization, cloud infrastructure, and observability.

Diagnose complex issues across services and infrastructure; lead incident investigation and resolution.

Run and participate in code reviews; mentor mid-level and junior developers.

Establish and uphold coding standards, security practices, and design principles across the team.

Who are we looking for

• 4+ years of professional Java development experience
• Experience with modern Java (latest LTS) and a mindset of keeping up with the newest stable language features and tooling.
• Proficiency in Java and object-oriented (and ideally functional) programming principles.
• Strong experience with Spring Boot and the Spring ecosystem, including Spring Security / OAuth2.
• Solid SQL and relational database experience (e.g. PostgreSQL), including schema design and query optimization.
• Experience with a schema migration / database versioning tool (e.g. Flyway, Liquibase).
• Proven experience designing and building RESTful APIs and integrating distributed services.
• Experience with containers (e.g. Docker) and CI/CD pipelines (e.g. Jenkins, GitLab CI)
• Strong experience with automated testing-unit and integration (e.g. JUnit, Testcontainers).
• Solid grasp of software architecture and design patterns (e.g. clean/hexagonal architecture, DDD).
• Solid Understanding of secure coding, resilience, and observability in production systems.
• Confident use of Git and modern branching/merging workflows.
• Private medical & life insurance
• Public transportation allowance
• Annual bonus.

We are proud to be an Equal Opportunity employer. We do not discriminate based upon race, religion, color, national origin, sex (including pregnancy, childbirth, or related medical conditions), sexual orientation, gender identity, gender expression, age, status as an individual with a disability, or any applicable legally protected characteristics.

Pursuant to the Article 24 sec. 6 of the Act of 14 June 2024 on the protection of whistleblowers, we inform you that Worldline Financial Services (Europe) S.A., a joint-stock company, Branch in Poland (hereinafter referred to as Worldline) is governed by the Regulations on the receipt of internal reports and taking follow-up actions (hereinafter referred to as the Regulations).

#LI- AS2

Shape the evolution

We are on an exciting journey towards the next frontiers of payments technology, and we look for big thinkers, people with passion, can-do attitude and a hunger to learn and grow. Here you'll work with ambitious colleagues from around the world, take on unique challenges as a team, and make a real impact on the society. With an empowering culture, strong technology and extensive training opportunities, we help you accelerate your career - wherever you decide to go. Join our global team of 18,000 innovators and shape a tomorrow that is yours to own.

Learn more about life at Worldline at jobs.worldline.com

We are proud to be an Equal Opportunity employer. We do not discriminate based upon race, religion, color, national origin, sex, sexual orientation, gender identity, gender expression, age, status as an individual with a disability, or any applicable legally protected characteristics.

Shape the evolution

We are on an exciting journey towards the next frontiers of payments technology, and we look for big thinkers, people with passion, can-do attitude and a hunger to learn and grow. Here you'll work with ambitious colleagues from around the world, take on unique challenges as a team, and make a real impact on the society. With an empowering culture, strong technology and extensive training opportunities, we help you accelerate your career - wherever you decide to go. Join our global team of 18,000 innovators and shape a tomorrow that is yours to own.

Learn more about life at Worldline at jobs.worldline.com

We are proud to be an Equal Opportunity employer. We do not discriminate based upon race, religion, color, national origin, sex, sexual orientation, gender identity, gender expression, age, status as an individual with a disability, or any applicable legally protected characteristics.