Start: August 24, 2026
Duration: August 6, 2027
Rate: max. €110, including MSP fee
Hours: 36–40 per week
Self-employed: No
Location: Arnhem
Screening: Basic (VOG)

Data Engineer
A temporary assignment lasting approximately 6 months is available for the ART Network Forecasting & Network Design team within the System Optimization department.

An exciting opportunity has opened up on the System Optimization team! We’re looking for a Senior Data/Software Engineer with a strong passion for data and data modeling to join this great team, ideally starting in Q4 2026 or Q1 2027. 

What will you be doing?
You’ll be joining us for a specific assignment. Our data model, which supports various applications, needs to be redesigned. This team has an extensive Python codebase, and you’ll be responsible for:

• Redesigning our data model;
• Developing, maintaining, and further enhancing the existing codebase
• Review, refactor, and improve code with a focus on quality, performance, and maintainability
• Collaborate with data scientists and software engineers to translate analytical logic into robust software
• Writing and maintaining automated tests (e.g., Pytest)
• Active coordination with colleagues both within and outside the team

What do you bring?

• Data Modeling: At least 9 years of demonstrable experience in modeling large, complex data models.
• Python expertise: At least 9 years of hands-on experience with Python (including object-oriented programming), experience with NumPy and modern testing frameworks such as Pytest. You write clear, reliable, testable, and scalable code (on AWS, using CDK).
• Tools and frameworks: Experiencewith tools such as Kubernetes, FastAPI, Django, Docker, and PostgreSQL.
• Code review and refactoring: Experience reviewing and improving complex codebases, providing constructive feedback, and optimizing code from other disciplines (e.g., data science).
• Cloud & workflow (preferred): Experience with the AWS stack, workflow tools (e.g., Argo), and CI/CD pipelines is a strong plus.
• Collaboration and Communication: You enjoy working as part of a team, clearly explain technical decisions, and are flexible and solution-oriented.
• Technical Curiosity: Broad interest in technology; comfortable working with multiple Python packages and tooling ecosystems.
• Net Calculations (Prerequisite): You enjoy net calculations (or would like to learn them).

About the System Optimization Team
You’ll be joining a really funteamthat supports the network architects every day. We hold our collaboration day on Thursdays (and optionally on Tuesdays) at Bellevue in Arnhem. We know the network inside and out and build HoloNet and HoloCube (tools that hundreds of people rely on).

We're looking for someone who:

• Enjoys making a hands-on impact on one of the company's most important target groups.
• She gets energy from working with data tech professionals.
• Every now and then, I like to grab a beer in Arnhem after work, preferably at Café Nelson, along with a "Mannenliefde."