Senior Java Backend Engineer — API & Cloud (Remote)

Worldline; Warszawa; Hybrid; PLN 240,000 - 360,000; Full time

Benefits offered by this job

Private medical & life insurance

Public transportation allowance

Annual bonus

Job summary

Worldline in Warsaw, Poland is seeking an experienced Senior Java Backend Developer for the Risk Technology Services team. You will drive end-to-end ownership from API design to cloud infrastructure, shaping resilient services and delivery pipelines.

You’ll mentor peers and influence architectural choices in a globally distributed context. The role demands hands-on development, collaboration, and a platform mindset to deliver secure, scalable solutions in a modern cloud environment.

Qualifications

• 4+ years of professional Java development.
• Strong Java, OOP (and some functional) programming mindset.
• Deep Spring Boot and Spring ecosystem experience, incl. Spring Security/OAuth2.
• SQL and relational DB experience (PostgreSQL), schema design and optimization.
• Experience designing RESTful APIs and distributed services.
• Containers (Docker) and CI/CD pipelines (Jenkins, GitLab CI).
• Automated testing at unit and integration levels (JUnit, Testcontainers).
• Knowledge of architecture patterns (clean/hexagonal, DDD) and secure coding.
• English communication skills; ability to lead in Agile and mentor peers.

Responsibilities

• Collaborate with cross-functional teams to deliver features and services.
• Own architecture decisions: service boundaries, APIs, data models.
• Design schemas and manage migrations with Flyway/Liquibase.
• Build RESTful APIs and asynchronous integrations between services.
• Apply resilience patterns and champion test-driven development.
• Contribute to CI/CD, containerization, cloud infra and observability.
• Diagnose complex issues, lead incident investigations, and mentor others.
• Review code, uphold coding standards and security practices.

Skills

Java

Spring Boot

Spring Framework

Spring Security/OAuth2

REST APIs

SQL PostgreSQL

Docker

CI/CD

Testcontainers

OpenTelemetry

DDD/Hexagonal architecture

AWS

Git/GitHub

Terraform/CloudFormation

Jenkins/GitLab CI

Java ecosystem knowledge

Tools

Flyway

Liquibase

OpenAPI/Spring REST Docs

MinIO / cloud storage emulation

Datadog / OpenTelemetry

Terraform / CloudFormation

Job description

Worldline in Warsaw, Poland is seeking an experienced Senior Java Backend Developer for the Risk Technology Services team. You will drive end-to-end ownership from API design to cloud infrastructure, shaping resilient services and delivery pipelines.

You’ll mentor peers and influence architectural choices in a globally distributed context. The role demands hands-on development, collaboration, and a platform mindset to deliver secure, scalable solutions in a modern cloud environment.