Interim Full stack backend developer

As a Software Engineer in the Developer Portal team, you’ll help shape the backbone of KPN’s developer experience. You’ll design, build, and maintain reliable, high-performing backend services and APIs that connect KPN’s internal and external ecosystems — from customers and suppliers to partners and developers. You’ll work in a modern cloud-native environment with .NET and Python, using event-driven and microservices architectures to deliver scalable and secure solutions.

You take ownership from design to deployment, value clean code and automation, and enjoy contributing to both the architecture and culture of your team.

Qualifications

We’re looking for a passionate engineer with a strong technical foundation and a collaborative mindset.

You bring:

• 5+ years of professional software development experience

• Solid understanding of OOP, clean code, and design principles (SOLID)

• Experience with microservices and event-driven architectures

• Hands-on skills with CI/CD, Docker, and Infrastructure as Code (IaC)

• Familiarity with REST APIs, OpenAPI/Swagger, and OAuth2

Nice-to-have experience with AWS, Python/Django, or .NET Core? Even better.

Additional Information

Apply before: November 19th 17:00
Starting date: december 1st 2025
Contract untill: june 1st 2026
Hours per week: 36 
Rate: maximum €89,00 (including travel expenses, excl BTW)

Wil je meer weten? Neem contact op met onze recruiter Antoine van der Maas via 06 – 30167124 of antoine.vandermaas@kpn.com.

About the Company

You’ll join an international team of 13 professionals — front-end and backend developers, API experts, and cloud engineers — all dedicated to making KPN’s developer experience seamless and powerful.
We collaborate closely, using Agile/Scrum principles and working two days a week from our Rotterdam office. Autonomy, trust, humor, and shared responsibility define our way of working.

We take pride in solving complex challenges while keeping the atmosphere open and supportive.