Junior Full Stack Developer Consultant

Mission Overview:

As part of a consultancy mission at a client site representing Keystone Solutions, we are looking for a Junior Full Stack Developer to strengthen existing delivery teams involved in the development, integration, and evolution of critical public sector digital services.

Key Activities:

• Development and maintenance of business-critical applications and shared services.
• Integration with internal and external systems through APIs and service-oriented architectures.
• Modernization, optimization, and continuous improvement of existing applications and technical platforms.
• Contribution to the implementation of secure and resilient digital services supporting public sector organizations.

Languages:

French or Dutch: Expert level
English: Working proficiency

Responsibilities:

• Development and maintenance of business applications and shared digital services.
• Development of application components, APIs, and web services.
• Contribute to the design of application architecture and technical building blocks in collaboration with technical leads and solution architects.
• Participate in technical workshops, Agile/Scrum ceremonies, and stakeholder meetings.
• Support testing activities, technical documentation, deployments, quality assurance, monitoring, reporting, and continuous improvement initiatives.
• Collaborate with multidisciplinary teams to ensure alignment with business and technical requirements.
• Ensure adherence to security, performance, interoperability, and quality standards.

Experience:

• Minimum 3+ years of professional experience in Java software development.
• Experience working in complex multi-system environments and large-scale digital transformation projects.
• Experience in public sector environments is considered an asset.
• Proven experience in Agile delivery environments.

Competencies:

• Technical knowledge and practical experience of the following technologies:
  • Java >= 21 and Spring Framework (Core, JDBC, Data, Security, AOP)
  • JPA / Hibernate
  • RESTful Web Services
  • OpenAPI / Swagger
  • Keycloak, Lombok, MapStruct
  • SOA, Backend-for-Frontend, CQRS
  • Test-driven development (JUnit, Mockito, Spring Test, Cypress)
  • Angular 20
  • Maven
  • Docker
  • OpenShift / Kubernetes
  • Git and GitLab CI/CD
  • SonarQube
  • NPM
  • OAuth 2.0
  • Flyway or Liquibase
  • PostgreSQL, SQL Server and relational databases
  • BPMN and UML
  • Jira and Confluence
  • Agile/Scrum methodologies
  • Continuous Integration and Continuous Delivery (CI/CD)

Soft Skills:

• Strong analytical and problem-solving skills.
• Ability to quickly understand and maintain existing codebases.
• Customer and solution-oriented mindset.
• Team player with strong communication skills.
• Autonomous, proactive, and quality-focused.

Mission & Working Conditions:

The mission is carried out within a hybrid working environment. Regular presence on site may be required depending on project needs and team activities. Collaboration with multidisciplinary teams across different public sector organizations.

Duration:

As soon as possible - 31/12/2026 4 months • (full time)

Skills required:

• Agile / Scrum - Level: Junior - Most recent: Any time
• Angular 17 - Level: Junior - Most recent: Any time
• Docker - Level: Junior - Most recent: Any time
• Java 11 + 17 - Level: Junior - Most recent: Any time
• JMS - Level: Junior - Most recent: Any time
• JPA - Level: Junior - Most recent: Any time
• Oracle - Level: Junior - Most recent: Any time
• REST - Level: Junior - Most recent: Any time
• Spring - Level: Junior - Most recent: Any time
• Springboot 2.x + springboot3 - Level: Junior - Most recent: Any time
• SQL - Level: Junior - Most recent: Any time
• test metghodologiën - Level: Junior - Most recent: Any time
• Weblogic - Level: Junior - Most recent: Any time

Language requirements:

French or Dutch: Expert level
English: Working proficiency

Responsibilities

• Development and maintenance of business applications and shared digital services.
• Development of application components, APIs, and web services.
• Contribute to the design of application architecture and technical building blocks in laboration with technical leads and solution architects.
• Participate in technical workshops, Agile/Scrum ceremonies, and stakeholder meetings.
• Support testing activities, technical documentation, deployments, quality