Senior Java Backend Engineer — Spring & APIs (Hybrid)

SEIDOR; Brussel; Hybrid; EUR 70,000 - 100,000; Full time

Job summary

SEIDOR is seeking an Advanced Java Developer to join our Brussels team in a hybrid work setup. You will design, develop and test backend components using the Spring ecosystem, implement REST and event-driven APIs, and contribute to CI/CD pipelines.

You will work on authentication, data persistence, and integration with messaging systems, while participating in code reviews and documenting APIs. Candidates should have strong Java back-end experience, extensive Spring expertise, and a solid

Qualifications

• 4 years of experience developing Java back-end applications.
• 6 years of experience with the Spring ecosystem (Spring Boot, Spring Security).
• 6 years of experience designing and implementing REST APIs and event-driven integrations.
• 5 years of experience with relational databases and ORM frameworks (Hibernate/JPA).
• 4 years of experience with development and DevSecOps tooling, including version control (Git), issue tracking (Jira/Confluence) and CI/CD pipelines (Jenkins/Bamboo).
• English level C1.
• Bachelor's degree in Computer Science (EQF level 6) or equivalent.

Responsibilities

• 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.

Skills

Java backend

Spring ecosystem

REST APIs

Event-driven

Relational databases

DevSecOps tooling

Git/Jira/CI/CD

Education

Bachelor's degree in Computer Science

Master's degree (advantage)

Tools

Docker

Kubernetes

Jira/Confluence

Git

Jenkins/Bamboo

Job description

SEIDOR is seeking an Advanced Java Developer to join our Brussels team in a hybrid work setup. You will design, develop and test backend components using the Spring ecosystem, implement REST and event-driven APIs, and contribute to CI/CD pipelines.

You will work on authentication, data persistence, and integration with messaging systems, while participating in code reviews and documenting APIs. Candidates should have strong Java back-end experience, extensive Spring expertise, and a solid