Together with the developers on your team, you design, build, and maintain the software that puts a smile on your colleagues’ and our customers’ faces.
- Employer
- Coolblue
- Location
- Rotterdam City, Rotterdam, ZH
- Pay
- €14.99/hour
- Hours
- 36-40 uur
- Language
- Dutch only
- Apply method
- Coolblue website
- Posted
- 12 May 2026
- Open until
- Not listed
Together with the developers on your team, you design, build and maintain the software that puts a smile on the faces of your colleagues and our customers.
What do you do as a C# Developer at Coolblue?
As a C# developer, together with your team, you are responsible for maintaining and developing products that support your domain. You do this by writing well-maintainable, testable and future-proof code. In addition, you regularly participate in brainstorming sessions about user experience, data and task flow with the UX Designer, Product Owner and Data Scientist in your domain.
- Solving problems using the best practices and principles we have embraced, such as Clean Architecture, TDD/BDD, SOLID and design patterns.
- Writing automated tests so that you know the quality of your software is on point.
- Working with different types of data storage, such as Oracle, MySQL and DynamoDB.
- Taking ownership of the solutions within your domain's portfolio by solving challenges in a timely manner using logging and monitoring in Datadog.
- Sharing knowledge through mentoring and pair programming sessions, and adding constructive comments to colleagues' pull requests in Github.
- Being given the opportunity to continue developing yourself and deepen your knowledge of the latest technologies.
- Giving and receiving constructive feedback.
- Presenting deliverables during sprint demos. Our toolbox is filled with:
- Programming language: C#.NET 8.0
- Data storage: Oracle, MySQL, PostgreSQL and DynamoDB.
- Cloud platform: AWS
- CI/CD: Github and TeamCity
- Logging/Monitoring: Datadog
Here's how you recognize yourself
- You have at least 3+ years (medior) or 6+ years (senior) of experience as a C# developer.
- You have a Bachelor’s or Master’s degree in Computer Science or a comparable field.
- Experience with software architecture and building applications 8.0.
- You have experience with Web API or MVC (REST & GraphQL).
- Knowledge of designing, setting up and maintaining cloud-native microservices, preferably in AWS.
- You feel like a fish in water when working with Scrum/Agile.
- Experience with front-end development (React), JavaScript, HTML5 and CSS is a plus.
- Being able to automate and implement repetitive tasks within a CI/CD platform. Experience with Teamcity is even better.
- You speak English very well.
What else you’re looking for in a job
- Money.
- Monthly drinks, freshly prepared snacks, legendary Coolblue parties and the best team activities.
- A great combination of working at the office and from home. Of course, we’ll make sure you have a top-notch workspace at home. Including an office chair, laptop and blue streamers.
- Plenty of room for your own ideas, initiatives and choices. You do your work your way.
- Travel allowance, pension scheme and an allowance for working from home.
- 25 vacation days. If you promise you’ll come back.
- Discount on everything we sell.
- An office you’ll want to take photos of in a prime location. From Rotterdam Centraal, it’s only 3 falls away. Okay, it’s 2 minutes on foot.
- More than 100 training courses at our own Studiefabriek to become a little better every day.