Senior Java Developer

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

Job summary

Onepoint in Belgium is seeking a Senior Full-Stack Java Developer to design, build and maintain modern web applications across backend and frontend.

You will work on RESTful APIs, Angular frontends, and contribute to architecture, performance, security and maintainability while mentoring junior developers. Join a collaborative team using CI/CD and agile practices to deliver high‑quality features.

Qualifications

• 5+ years of professional Java development experience.
• Strong Spring Boot and REST API experience.
• Frontend experience with Angular and TypeScript.
• Enterprise‑level app experience focusing on performance, security and maintainability.
• CI/CD and Agile environment experience.

Responsibilities

• Design, develop and maintain backend services using Java and frameworks.
• Build and enhance RESTful APIs to support web and mobile applications.
• Develop responsive frontend interfaces using Angular.
• Participate in architecture discussions focusing on performance, scalability and security.
• Write clean, tested, and well‑documented code following best practices.
• Collaborate with product owners, business analysts and other developers to refine requirements and deliver features.
• Troubleshoot and resolve complex issues across the stack.
• Contribute to code reviews, knowledge sharing and mentoring of junior developers.
• Participate in CI/CD, release management and lifecycle improvements.

Skills

Java

Spring Boot

REST APIs

Angular

TypeScript

SQL/ORM

CI/CD

Agile/Scrum

Microservices

Architectural patterns

Job description

Contribute to the major transformations of companies and public actors by combining technological innovation and business expertise, serving our society and customers to help them move forward sustainably.

Your responsibilities for this function :

We are looking for a Senior Full‑Stack Java Developer to join our client’s development team and take a key role in designing, building and maintaining modern web applications. You will work across the entire stack (backend and frontend), contribute to architecture and technical choices, and help raise the overall engineering standards within the team.

• Design, develop and maintain backend services using Java and related frameworks.
• Build and enhance RESTful APIs to support web and mobile applications.
• Develop responsive, user‑friendly frontend interfaces using modern JavaScript frameworks (e.g. Angular).
• Participate in technical design and architecture discussions (performance, scalability, security, maintainability).
• Write clean, testable, and well‑documented code following best practices and coding standards.
• Collaborate closely with product owners, business analysts and other developers to refine requirements and deliver high‑quality features.
• Troubleshoot, debug and resolve complex technical issues across the stack.
• Contribute to code reviews, knowledge sharing and mentoring of more junior developers.
• Participate in CI/CD, release management and continuous improvement of the development lifecycle.

Your skills:

• 5+ years of professional experience as a Java developer, including senior responsibilities.
• Strong experience with Spring / Spring Boot and RESTful API development.
• Solid experience in frontend development with Angular (or similar framework, with willingness to focus on Angular).
• Proven experience working on complex, enterprise‑level applications (performance, security, maintainability).
• Good understanding of software architecture patterns (layered architecture, microservices, clean architecture, etc.).
• Strong knowledge of relational databases and ORM tools.
• Experience with CI/CD pipelines, automated testing and modern software engineering practices.
• Ability to work in an Agile/Scrum environment and collaborate with cross‑functional teams.

Core Technical Stack

Backend:

• Java 8+ / 11+
• Spring, Spring Boot
• Java EE / Jakarta EE (JPA, EJB, JMS, Servlet, etc.)
• RESTful web services (REST)
• API design and integration (JSON, XML)
• JPA / Hibernate or other ORM frameworks
• Microservices architectures (Spring Cloud / similar)

Frontend:

• Angular (latest versions preferred)
• TypeScript / JavaScript (ES6+)
• HTML5, CSS3, SCSS
• Responsive design and UI frameworks (Bootstrap / Material / similar)

Integration & Data:

• Relational databases (Oracle, PostgreSQL, MySQL, SQL Server) and strong SQL skills
• Messaging / event‑driven architectures (JMS, Kafka, RabbitMQ or similar)
• API gateways and security (OAuth2, JWT, OpenID Connect)

Onepoint in a few words:

In just over 20 years, Onepoint has become one of the major players in consulting and tech. Indeed, our collective has now more than 3,500 people around the world (France, Australia, Belgium, Canada, Malaysia, Morocco and Singapore). Our turnover has been multiplied by 10 in only 10 years, reaching more than 500 million euros, and aims to reach a billion euros within 4 years.