Senior Java Backend Engineer – Cloud, APIs & Resilience

Worldline; Warszawa; On-site; PLN 210,000 - 320,000; Full time

Benefits offered by this job

Private medical & life insurance

MyBenefit Platform

Holiday allowance

Public transportation allowance

Meal allowance

Annual bonus

Job summary

Worldline is seeking a Senior Java Backend Developer for Risk Technology Services. You’ll engage in architecture discussions, own end-to-end delivery from APIs to cloud pipelines, and mentor teammates.

You’ll work hands-on in a collaborative, fast-paced environment to build scalable services with strong security, performance, and reliability. Expect close cross-functional teamwork, design of service boundaries, and ownership of data models and migrations.

Qualifications

• 4+ years of professional Java development.
• Modern Java (latest LTS) and up-to-date tooling.
• Proficiency in Java and OOP with functional style where relevant.
• Strong Spring Boot and Spring ecosystem experience, incl. Spring Security/OAuth2.
• Solid SQL and relational DB experience, incl. PostgreSQL
• Schema migrations with Flyway or Liquibase.
• Designing RESTful APIs and integrating distributed services.
• Containers and CI/CD pipelines (Docker, Jenkins, GitLab CI).
• Strong automated testing – unit/integration with JUnit/Testcontainers.
• Good software architecture understanding and design patterns.
• Secure coding, resilience and observability in production.
• Proficient in Git and modern branching workflows.
• Ability to lead in Agile environments and mentor others.
• AI-assisted development awareness and practices.
• Asynchronous/event-driven integrations with messaging systems.

Responsibilities

• Collaborate with cross-functional teams to deliver new features and services; set technical direction for Risk tech service.
• Own architecture and design decisions: service boundaries, APIs, data models, and cross-service contracts.
• Design database schemas and manage evolution via migrations.
• Build RESTful APIs and asynchronous/event-driven integrations between services.
• Apply resilience patterns and champion test-driven development with strong coverage.
• Own delivery: CI/CD pipelines, containerization, cloud infra, observability.
• Diagnose complex issues across services and infrastructure; lead incident investigations.
• Mentor mid-level and junior developers; participate in code reviews.
• Establish and uphold coding standards, security practices, and design principles.

Skills

Java

Spring Boot

Spring Framework

Spring Security/OAuth2

SQL

Flyway

Docker

CI/CD

JUnit

Testcontainers

OpenTelemetry

Git

Distributed systems

Agile

RESTful APIs

Tools

AWS

GCP

Terraform

CloudFormation

Kubernetes

Jenkins

GitLab CI

OpenAPI

Job description

Worldline is seeking a Senior Java Backend Developer for Risk Technology Services. You’ll engage in architecture discussions, own end-to-end delivery from APIs to cloud pipelines, and mentor teammates.

You’ll work hands-on in a collaborative, fast-paced environment to build scalable services with strong security, performance, and reliability. Expect close cross-functional teamwork, design of service boundaries, and ownership of data models and migrations.