Senior Java Backend Developer​/Integration Engineer

We are looking for a 5 Senior Java Backend Developers / Integration Engineers to strengthen the team working in pharma sector, a strategic integration platform in the healthcare ecosystem. This role is ideal for someone who enjoys building reliable backend services, secure APIs, event-driven integrations, and cloud-connected data flows in a modern Java environment.

You will join a team responsible for the evolution of the solution, a multi-module platform built around integration, interoperability, security, and data exchange.

• Designing and implementing backend features in a modern Java stack
• Building and maintaining secure APIs and gateway flows
• Developing integrations with external systems and healthcare partners
• Working on event-driven communication and asynchronous processing
• Contributing to data persistence, migration, and operational reliability
• Supporting cloud-based data exchange patterns and AWS-connected services
• Ensuring code quality through unit and integration testing
• Collaborating closely with analysts, architects, and product stakeholders

The current stack includes:

• Spring Boot 4
• Spring Cloud Gateway
• Spring Web Flux
• Spring Security
• Spring Data JPA
• MariaDB
• Flyway
• Redis
• JWT / OAuth2 Resource Server
• AWS SDK with S3 , Glue , Athena
• OpenAPI / Springdoc
• Jackson
• Parquet / Hadoop
• Maven
• JUnit 5 / Mockito

• Strong experience in backend development with Java and Spring
• Solid knowledge of API design, security, and system integration
• Experience with relational databases such as Maria
  
  DB or MySQL
• Experience with messaging platforms such as Kafka
• Familiarity with cloud environments, ideally AWS
• Good understanding of authentication and authorization mechanisms such as JWT and OAuth2
• A quality-driven mindset with attention to testing, maintainability, and production reliability
• The ability to work autonomously while collaborating effectively with a broader team

• Experience with Spring Cloud Gateway or API gateway patterns
• Experience with Redis
• Exposure to healthcare, interoperability, or regulated environments
• Experience with data pipelines or analytical storage flows using S3 / Athena / Glue
• Familiarity with hexagonal architecture or domain-driven design principles

• Strategic project with real business and integration impact
• Modern Java and Spring ecosystem
• Combination of backend engineering, integration, security, and cloud topics
• Collaborative team environment
• Opportunity to contribute to a platform used in a sensitive and meaningful domain

• Location:
  
  Belgium / hybrid possible
• Engagement: freelance or employee, depending on profile
• Duration: long-term reinforcement for the team