Back-End/ API Developer

We are looking for a Senior Back-End/API Developer for a major client based in Luxembourg (on-site).

🎯 What you will work on

• Developing Java back-end applications with Spring Boot and building vendor-neutral, portable services.
• Designing and integrating RESTful APIs and supporting interoperability across distributed systems.
• Implementing secure credential management using HashiCorp Vault and established security practices.
• Managing builds and dependencies with Maven in complex, multi-module environments.
• Working with PostgreSQL and Oracle PL/SQL, configuring database changes with Liquibase or similar tools.
• Containerizing applications using Docker in cloud-agnostic architectures.
• Integrating Kafka for event-driven communication and managing distributed data schemas.
• Applying CI/CD practices with Git, automated testing, and deployment pipelines.
• Performing back-end testing with JUnit, Mockito, Postman and Testcontainers.
• Implementing cloud and monitoring solutions across AWS, Azure or GCP, and creating dashboards using ELK.
• Collaborating within Agile/Scrum teams, using Jira, Confluence, SharePoint and Teams.

📌 Requirements

All requirements below are mandatory for this role.

Java Development

• 8+ years with Java (8 to 21), Spring Boot, Maven.

API Development

• 5+ years with RESTful APIs, plus 1 year with GraphQL, WSO2 API Gateway (or similar).

Security & Credential Management

• 4+ years securing applications under standards like SSDF, NIST 800-53, plus 2 years with HashiCorp Vault experience.

Databases & Data Formats

• 6+ years with SQL, XML, HTML, JSON, plus 2 years with RDF, knowledge graphs, triple stores.

Containerization

• 2+ years with Docker, plus 1 year with cloud-agnostic environments.

Event-Driven Architecture

• 3+ years with Apache Kafka, schema management (Schema Registry), and 2 years in monitoring Kafka flows.

CI/CD & Compliance

• 3+ years with CI/CD and Git, plus 1 year in licensing/compliance management.

Testing

• 5+ years with JUnit, Mockito, Postman, Testcontainers (or similar).

Cloud Platforms & Monitoring

• 5+ years with AWS, Azure, GCP, SaaS/CaaS, monitoring tools such as ELK Stack, and designing dashboards.

Agile & Collaboration

• 5+ years in Agile/Scrum environments, using Atlassian tools, plus 1 year with Microsoft SharePoint and Teams.

Documentation & Communication

• 5+ years in documenting code/configurations, and 3 years in writing analysis documents and technical guides.

🎓 Education

• Bachelor's degree or 3 years of higher education in IT, Computer Science, or related field.

🗣 Languages

• English: C1
• French: B2