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SEIDOR

Full-stack developer - Brussels - Near site

Hybrid

Uccle, Belgium

Mid level

Freelance

19-01-2026

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Skills

JavaScript PHP Jira MySQL GitLab CI/CD DevOps Configuration Management Version Control Scrum git symfony Agile HTML5

Job Specifications

We are on the lookout for a Full-stack developer to join our team for working with European Institutions based in Brussels in an Near site position.

Get to know us - SEIDOR

At SEIDOR, we drive client transformation and competitiveness with cutting-edge technology and innovation , with a relentless focus on the human element and a commitment to nurturing talent and sustainable growth.

As a diverse and inclusive company that champions equal opportunity, we boast a team of over 8,000 professionals in our global presence across 45 countries in Europe, Latin America, the USA, the Middle East, Africa, and Asia.

We believe the digital world's challenges require not only the best technologies and partnerships but most importantly, the best people. That's where you come in – we need you to help us scale new heights.

For this position you would be working with our client from the European institutions.

Below are the details of your role and requirements.

Your role

1- Development and Maintenance

Develop, maintain, and optimise Drupal 10 back-end functionalities
Build and customize Twig templates for Drupal
Implement and optimise existing Commission modules (“OpenEuropa” components) or build scalable, secure, and performant custom ones based on business needs and following Drupal coding standards
Develop and maintain CKEditor custom components
Implement data structures such as content types, views, blocks, taxonomies, and entity references
Integrate RESTful APIs, including content synchronisation and dynamic data visualisation
Support multilingual setups
Optimise performance and scalability of the platform

2- Platform Operations and Support

Troubleshoot and resolve back-end bugs, performance issues and integration mismatches
Support deployment and environment management (e.g. local/ACC/PROD)
Document development, deployment, and configuration procedures

3- Collaboration and Agile processes

Use GitLab for version control and CI/CD workflows
Manage work in JIRA or similar ticketing systems following Agile/Scrum methodologies
Participate in scrum meetings, technical reviews, sprint planning, and knowledge-sharing activities
Collaborate closely with developers, business analysts, and end-users

What’s in it for you?

From day one, you’ll find opportunities for personal and professional development within a supportive team environment. We offer:

A permanent role at a leading tech project firm (subcontractor also possible).
A hybrid work schedule, blending in-office collaboration with the convenience of working from home.
Continuous learning and development through SEIDOR Academy.
A package including salary and additional annual bonus, working equipment, phone and other benefits.
A dynamic international workplace with diverse teams.
A commitment to your well-being, work-life balance, and career growth.
Rapid advancement opportunities in a short period of time.
Engaging events and a comprehensive onboarding program.

At SEIDOR, Your Growth Is Our Success, And We Strive To Make Our Workplace Feel Like Home. Discover The Nine Core Aspects Of Our Culture That Define Us At SEIDOR

https://www.seidor.com/en-es/talent

If this resonates with you, we'd love for you to apply to our opening, and we'll be in touch soon!

Requirements

Who we think you are:

SPECIFIC EXPERTISE

At least 5 years of specific expertise in Drupal development
At least 2 years of experience in PHP, Twig, and Drupal theming
At least 2 years of experience working with multilingual/multisite Drupal platforms.

Knowledge And Skills

We are seeking a versatile Full-stack Developer with expertise in Drupal. The ideal candidate should be comfortable developing secure and scalable Drupal back-end solutions as well as implementing modern, responsive front-end interfaces that meet the European Commission’s accessibility and performance standards.

Following skills and knowledge are required for the performance of the above listed tasks:

1- Drupal Back-End Expertise

Proven experience with Drupal 9/10/11
Strong command of PHP and Symfony components
Experience with Drupal configuration management, using Drush, Composer, and Git
Familiarity with custom entities, field types, plugins, hooks, and services
Understanding of multilingual setups, translation workflows, and editorial permission structures
Knowledge of Drupal security practices, including secure coding, form validation, and sanitisation

2- Drupal Front-End Expertise

Experience theming Drupal using Twig, HTML5, CSS3, and modern JavaScript (ES6+)
Ability to transfer wireframes into functional, responsive and accessible interfaces
Understanding of accessibility requirements (e.g., WCAG) and user-centred design principles

3- API and Integration

Experience integrating RESTful APIs in Drupal

4- Database and Performance

Experience working with MySQL
Familiarity with performance optimisation (e.g. caching strategies, lazy loading, query tuning)

5- DevOps and Version Control

Experience using GitLab

About the Company

At SEIDOR we help drive the transformation and competitiveness of our clients through technology and innovation, always focusing on the human value and prioritizing talents and sustainable development. We are a diverse and inclusive organization that champions in equal opportunities, with over 9,000 professionals across 45 countries in Europe, Latin America, the United States, the Middle East, Africa, and Asia. From day one, you will have the opportunity to grow both professionally and personally, supported by a dedicat... Know more