Java Developer Senior - On site - Brussels

SEIDOR; Brussel; On-site; EUR 70,000 - 100,000; Full time

Job summary

SEIDOR in Brussels is seeking a Senior Java Developer to design, build and test back-end components using the Spring ecosystem. You will implement REST and event-driven APIs, ensure robust security with OAuth 2.0 / OIDC / SAML, and contribute to CI/CD pipelines in a collaborative environment.

You will work across code reviews, pair programming, documentation, and deployment support, while mentoring junior developers and making technical design decisions to optimise performance and security.

Qualifications

• 4 years of experience developing Java back-end applications.
• 8 years of Spring ecosystem experience (Spring Boot, Spring Security, Spring Data).
• 8 years designing REST APIs and event-driven integrations.
• 6 years with relational databases and ORM (Hibernate/JPA).
• 5 years DevSecOps tooling, incl. Git, Jira/Confluence, and CI/CD pipelines.
• 3 years as technical lead of a back-end team with design decisions and security optimization.
• English: level C1.
• Bachelor's degree (EQF level 6) in Computer Science or equivalent.

Responsibilities

• Design, develop and unit-test back-end components using the Spring ecosystem
• Implement REST and event-driven APIs and business logic
• Implement persistence layers and integrate with messaging systems
• Implement authentication and authorisation (OAuth 2.0 / OIDC / SAML)
• Contribute source code and configuration to the customer's CI/CD pipeline
• Participate in code reviews and pair programming
• Produce and maintain API documentation
• Identify, debug and fix defects; support deployment and migration activities

Skills

Java back-end

Spring ecosystem

REST API design

Event-driven integration

DevSecOps tooling

Technical leadership

Code reviews

API documentation

OAuth 2.0 / OIDC / SAML

Security optimisation

Git & CI/CD

Education

Bachelor's degree (CS)

Master's degree (CS)

Tools

Kafka

RabbitMQ

Docker

Kubernetes

Jenkins

Bamboo

Jira

Confluence

Job description

About The Job

SEIDOR is a multinational technology company with a start-up spirit. We organize ourselves into expert knowledge Units that collaborate with each other. That's why we are looking for curious individuals who are motivated by challenges and eager to grow personally and professionally, to join our team and make a positive impact on the world through technology.

ARE YOU UP FOR THE CHALLENGE?

We want you to be a part of our team, in Brussels, as a Senior Java Developer.

WHAT WILL YOU DO IN YOUR DAY-TO-DAY?

• Design, develop and unit-test back-end components using the Spring ecosystem
• Implement REST and event-driven APIs and the underlying business logic
• Implement persistence layers and integrate with messaging systems
• Implement authentication and authorisation (OAuth 2.0 / OIDC / SAML)
• Contribute source code and configuration to the customer's CI/CD pipeline
• Participate in code reviews and pair programming
• Produce and maintain API documentation
• Identify, debug and fix defects; support deployment and migration activities

Requirements

If holding a Bachelor's degree at least 15 years of experience, if holding a Master's degree at least 13 years of experience.

• 4 years of experience developing Java back-end applications
• 8 years of experience with the Spring ecosystem (Spring Boot, Spring Security, Spring Data)
• 8 years of experience designing and implementing REST APIs and eventdriven integrations
• 6 years of experience with relational databases and ORM frameworks (e.g. Hibernate/JPA)
• 5 years of experience with development and DevSecOps tooling, including version control (Git), issue tracking (e.g. Jira or equivalent), collaboration (e.g. Confluence or equivalent) and CI/CD pipelines (e.g. Jenkins, Bamboo or equivalent)
• 3 years of experience as technical lead of a back-end development team, including technical design decisions, definition of coding standards and performance and security optimisation

English: level C1

Educational Level required: Bachelor's degree (EQF level 6) in Computer Science, or equivalent

Nice To Have

• Experience with messaging/event platforms (e.g. Kafka, RabbitMQ)
• Experience with containerisation and orchestration (e.g. Docker, Kubernetes)
• Experience developing back-end applications in at least one of the customer's business domains (event management, safety and security, or document management)