Senior Mendix Developer

CGI Nederland; Randstad; On-site; EUR 90,000 - 120,000; Full time

Benefits offered by this job

Immediate permanent contract

Part-time possibilities

CGI shareholder

Job summary

CGI Nederland is seeking a Mendix Senior Developer / Technical Lead in the Randstad region to drive the technical delivery of Mendix solutions. You will lead development teams, shape architecture, ensure best practices, and partner with stakeholders to deliver scalable, maintainable applications.

The role emphasizes hands-on delivery, code reviews, performance optimization, and governance, with opportunities to mentor junior staff and contribute to solution design across projects.

Qualifications

• 5+ years Mendix development experience.
• Experience leading development teams or acting as a technical lead.
• Mendix Advanced and/or Expert Certification preferred.
• Good command of Dutch, written and spoken.
• Demonstrable work experience with databases.

Responsibilities

• Provide technical leadership and mentorship to junior and medior developers.
• Drive adoption of Mendix best practices across the team.
• Review solution designs, integrations, security configurations, and data models.
• Lead performance optimization initiatives.
• Collaborate with Product Owners, Business Analysts, Architects, and Operations teams.

Skills

Mendix development

Technical leadership

Solution architecture

Team mentoring

CI/CD & monitoring

REST/SOAP integrations

Education

Technical HBO/WO education

Tools

Robot framework

Playwright

Mendix unit testing

Databases

Job description

• Deep expertise in Mendix application development.

Position Description

Note: This job posting has a strong preference for Dutch speakers.

Your role in our team

The Mendix Senior Developer / Technical Lead is responsible for leading the technical delivery of Mendix solutions while remaining actively involved in development activities. This role provides technical leadership to the team, supports solution architecture decisions, ensures adherence to best practices, and drives application performance, scalability, and maintainability. The Senior Developer works collaboratively with developers, architects, business stakeholders, and project teams to deliver high‑quality business solutions.

Experience

• 5+ years of Mendix development experience.
• Proven experience working on enterprise-scale and production‑critical applications.
• Demonstrated experience leading development teams or acting as a technical lead.
• Mendix Advanced and/or Expert Certification preferred.

Technical Requirements

• Deep expertise in Mendix application development.
• Strong understanding of solution architecture and application design principles.
• Advanced domain modelling expertise.
• Extensive experience with integrations (REST, SOAP, APIs, external systems).
• Strong knowledge of Mendix security, performance optimization, scalability, and governance.
• Experience with CI/CD, monitoring, and production support.
• Ability to review application architecture and identify improvement opportunities.
• Experience establishing development standards and best practices.

Additional Requirements

• A completed (technical) HBO/WO education, preferably in Business Informatics;
• Good command of the Dutch language, both written and spoken.
• Affinity with user experience design
• Affinity with (Mendix) testing frameworks, such as Mendix unit testing, Robot framework, and Playwright;
• Demonstrable work experience with databases

Key Responsibilities

Technical Leadership

• Provide technical leadership and mentorship to junior and medior developers.
• Support team members in resolving complex technical challenges.
• Conduct code reviews and ensure development quality standards are maintained.
• Drive adoption of Mendix best practices across the team.

Solution Architecture

• Guide application architecture decisions and technical design.
• Assess technical feasibility of business requirements.

Delivery & Quality

• Participate in hands‑on development of critical features and components.
• Review solution designs, integrations, security configurations, and data models.
• Ensure development standards, security guidelines, and governance requirements are met.
• Identify technical risks and implement mitigation strategies.

Performance & Continuous Improvement

• Lead performance optimization initiatives.
• Review application performance metrics and recommend improvements.
• Drive technical debt reduction and application modernization efforts.
• Promote reusable components, standardization, and continuous improvement.

Team Collaboration

• Work closely alongside the development team rather than solely directing activities.
• Foster a collaborative and supportive team environment.
• Coordinate with Product Owners, Business Analysts, Architects, and Operations teams.
• Support planning, estimation, and delivery commitments.

Required Competencies

• Strong leadership and mentoring skills.
• Excellent problem‑solving and analytical abilities.
• Collaborative and team‑oriented mindset.
• Ability to balance technical excellence with delivery objectives.
• Proactive ownership and accountability.
• Strong focus on coaching and enabling team success.

Why CGI?

CGI is one of the world's largest IT consultancy firms. Our people keep the Netherlands running. Government agencies, banks, (aero‑) space, infrastructure organizations and energy and manufacturing companies are clients of CGI. We work on interesting projects that touch the daily lives of millions of people. We are present regionally, augmented with global domain knowledge, our ecosystem, and colleagues spread all over the world. We are proud of the impactful projects that we, together with our colleagues, make a success.

At CGI, we place great value on diversity and inclusion, as this not only promotes collaboration but often leads to better results. We look forward to your contribution to our team!

• Work in small self‑managing teams consisting of experts in your field
• Take control of your own career with the space to continue developing yourself
• You work with the latest technologies
• An excellent salary and attractive secondary employment conditions
• Immediate permanent contract
• Part‑time possibilities
• And the opportunity to become a CGI shareholder

Your future duties and responsibilities

Required Qualifications To Be Successful In This Role

Together, as owners, let’s turn meaningful insights into action.

Life at CGI is rooted in ownership, teamwork, respect and belonging. Here, you’ll reach your full potential because…

You are invited to be an owner from day 1 as we work together to bring our Dream to life. That’s why we call ourselves CGI Partners rather than employees. We benefit from our collective success and actively shape our company’s strategy and direction.

Your work creates value. You’ll develop innovative solutions and build relationships with teammates and clients while accessing global capabilities to scale your ideas, embrace new opportunities, and benefit from expansive industry and technology expertise.

You’ll shape your career by joining a company built to grow and last. You’ll be supported by leaders who care about your health and well‑being and provide you with opportunities to deepen your skills and broaden your horizons.

That same commitment to fairness extends to how we use technology. To support our recruitment team, AI tools may be used to help assess applications though they never replace human judgement. All hiring decisions remain entirely in the hands of our recruitment professionals.

Come join our team - one of the largest IT and business consulting services firms in the world.