Mendix Developer – Public Sector – Brussels

HumanInTech; Brussel Hoofdstad; Hybrid; EUR 45,000 - 60,000; Full time

Job summary

HumanInTech seeks an experienced application developer to work on a Mendix-based landscape in a hybrid Brussels setting. You will build new features, create screens, microflows, and integrations while collaborating with ICT and external partners.

Requirements include Mendix development experience, intermediate certification or higher, and strong English/Dutch/French language skills. The role is 12 months from January 2027, with options as freelancer or employee of HumanInTech.

Qualifications

• Confirmed experience as an application developer.
• Proven Mendix development experience and certification is preferred.
• Experience with Agile and Scrum methodologies.
• Experience with complex business processes.

Responsibilities

• Developing new functionalities and implementing user stories.
• Creating screens, microflows and integrations.
• Integrating with internal and external systems.
• Performing tests and quality assurance.
• Writing technical documentation.
• Supporting maintenance activities.
• Optimising performance, security and user experience.
• Contributing to migration and modernisation projects.
• Analyzing and implementing new business requirements.
• Transferring knowledge to internal teams.

Skills

Mendix development

Agile/Scrum

Multilingual: Dutch, French, English

Mid-level experience

Education

Bachelor's degree

Job description

What you will do

You will join a multidisciplinary team working on the continued development and evolution of a Mendix-based application landscape. The organisation has invested actively in digitalising its processes and applications using the Mendix low-code platform, and you will help ensure continuity, maintainability and further growth.

Your responsibilities include:

• Developing new functionalities and implementing user stories
• Creating screens, microflows and integrations
• Integrating with internal and external systems
• Performing tests and quality assurance
• Writing technical documentation
• Supporting maintenance activities
• Optimising performance, security and user experience
• Contributing to migration and modernisation projects
• Analysing and implementing new business requirements
• Transferring knowledge to internal teams

You will work according to Agile and Scrum principles, in close collaboration with business services, the ICT department and external partners. Depending on priorities and available budgets, you may be deployed on new projects, extensions of existing applications, maintenance and support, optimisation initiatives, or migration projects.

What we are looking for

• Confirmed experience as an application developer
• Confirmed experience with Mendix development
• Mendix Intermediate Advanced Developer certification or higher
• Confirmed experience with Agile and Scrum methodologies
• Confirmed experience with complex business processes
• Active knowledge of Dutch, French and English

The setting

This assignment runs for 12 months starting in January 2027. You will work in a hybrid mode from Brussels. The work is organised on the basis of separate orders according to the organisation's needs, and the actual start and volume depend on budget availability.

Selection is based on relevant experience, relevant competencies, quality of the proposed profile, Mendix certifications and price. All requested certificates and documents must be provided and verifiable.

You can join us for this assignment as a freelancer or as an employee of HumanInTech. Same role, same team. If you join as an employee, your employment continues beyond this assignment. When it ends, we’ll work together to find your next assignment.

Location: Brussels, hybrid

Work address: Belgium

Employer / contracting party: HumanInTech

Applications close (Brussels time): November 18, 2026 at 1:00 AM

Engagement: Freelance or employed by HumanInTech

Working hours: Full-time

Experience: 3–5 years or more

Education: Bachelor's or more

Published: November 2026