Fullstack Developer

SEIDOR; Brussel Hoofdstad; On-site; EUR 90,000 - 130,000; Full time

Job summary

SEIDOR in Brussels is seeking a senior Full Stack Software Engineer to design, develop, and maintain scalable web applications across front-end and back-end layers, with API integration and cloud deployment via CI/CD.

You will work in cross-functional teams, ensure code quality, security, and performance, and contribute to documentation and testing. A track record in complex software environments is highly valued.

Qualifications

• Computer Science, Engineering or equivalent Degree related
• 15 years of IT related experience
• 3 years of experience in international/intergovernmental organizations or central national administrations
• 1 year of experience in pharma, health or agrifood sectors
• Experience using Java and Java Enterprise (JDK 11+; JEE 7+) with middleware such as Oracle WebLogic (14+), TomEE or IBM WebSphere
• Experience developing and maintaining features across the full stack—from UI to API to database
• 3 years of experience with version control systems (Git, SVN) and CI toolchains (Bamboo, Jenkins)
• 5 years of experience in core frontend languages (JavaScript, HTML, CSS)
• 5 years of experience in modern frontend frameworks (Angular, React, Vue, Bootstrap, Dojo)
• 5 years of experience with relational databases (Oracle, PostgreSQL)
• 5 years of experience designing, building, securing RESTful APIs and web services
• 5 years of experience checking detail in code, error handling, and documentation
• 5 years of experience in root-cause analysis and debugging across software stack
• One certification in Java SE/Java EE/Oracle/IBM/Cloud computing

Responsibilities

• Design, develop, and maintain scalable full-stack web applications (front-end, back-end, database)
• Develop responsive user interfaces and server-side business logic
• Design, develop, and integrate APIs for seamless component communication
• Write clean, reusable, secure, well-documented code
• Implement authentication, authorization, input validation, secure storage, and monitoring
• Optimize performance, functionality, and cross-browser/device compatibility
• Perform unit and integration testing, debugging, and code validation
• Deploy and manage applications on cloud platforms using CI/CD pipelines and containers
• Collaborate with front-end and back-end teams for system integration
• Ensure solutions meet functional and non-functional requirements, maintain documentation and code quality

Skills

Analytical thinking

Root-cause analysis

Documentation

Team collaboration

Security best practices

Testing

Problem solving

Education

Bachelor's degree in Computer Science, Engineering or related

Tools

Java

Java Enterprise (JEE)

Oracle WebLogic

TomEE

IBM WebSphere

JavaScript

HTML

CSS

Angular/React/Vue/Bootstrap/Dojo

RESTful APIs

Git

Jenkins/Bamboo

Job description

About The Job

We are a large 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, from Brussels, as a Full stack Software Engineer.

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

• Design, develop, and maintain scalable full-stack web applications, covering front-end architecture, back-end systems, and database interactions.
• Develop responsive user interfaces and implement server-side business logic.
• Design, develop, and integrate APIs to ensure seamless communication between application components.
• Write clean, reusable, maintainable code following development and security best practices.
• Implement authentication, authorization, input validation, secure data storage, and monitoring.
• Optimize application performance, functionality, and cross-browser/device compatibility.
• Perform unit and integration testing, debugging, troubleshooting, and code validation.
• Deploy and manage applications on cloud platforms using CI/CD pipelines and containerization technologies.
• Collaborate with front-end and back-end teams to ensure seamless system integration.
• Ensure solutions meet functional and non-functional requirements while maintaining technical documentation and code quality.

WHAT DO WE EXPECT FROM YOU?

The Consultant Must Demonstrate Experience In

• Computer Science, Engineering or equivalent Degree related
• Minimum 15 years of IT related experience
• 3 years of experience working in international/intergovernmental organizations or central national administrations.
• 1 year of experience working in the pharma, health or agrifood sectors.
• Experience using Java and Java Enterprise (JDK up to at least version 11 or more recent versions, JEE up to at least version 7 or more recent versions) using web application server middleware such as Oracle WebLogic (up to at least version 14 or more recent versions), TomEE or IBM WebSphere.
• Experience developing and maintaining features across the entire stack, from designing user interfaces and consuming APIs to implementing server-side business logic and database interactions.
• 3 years of experience using version control systems (such as Git, SVN or equivalent) and continuous integration toolchains (Bamboo, Jenkins or equivalent).
• 5 years of experience in fundamental front-end languages such as JavaScript, HTML, CSS.
• 5 years of experience in modern front-end web frameworks (such as AngularJS, Angular, React, Vue, Bootstrap, Dojo or equivalent).
• 5 years of experience working with relational databases such as Oracle or PostgreSQL or equivalent.
• 5 years of experience in designing, building, and securing RESTful APIs and web services.
• 5 years of experience in checking detail in code correctness, error handling, and documentation.
• 5 years of experience in analyzing complex issues, running root-cause analyses, diagnosing problems throughout the software stack and designing effective solutions.
• One certification in at least one of following domains or equivalent:
• Java SE
• Java EE
• Oracle
• IBM
• Cloud computing