Senior Java Backend Engineer - Build Scalable APIs & Cloud

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 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.