.NET Developer (Freelance)

Passionate about tech, digital, and innovation? Join the 1,800 employees at Smile, the European leader in open-source integration, spread across 20 agencies in 9 countries. Collaborative spirit and knowledge sharing are at the heart of our DNA. Our experts push the boundaries every day to build a smarter, more efficient, and more responsible digital world. Here, we don’t just follow trends, we create them! Join Smile in Brussels and take part in projects that truly matter!

We are currently looking for a talented .NET Developer (Freelance) to join our dynamic team and work on high-impact projects for one of our major clients.

Position Overview

• Status: Freelance

• Location: Brussels, Belgium (Hybrid model: 2-3 days of remote work per week)

Your Responsibilities
As a .NET Developer, your daily missions will include:

• Designing and developing robust, scalable, and high-performance applications and APIs using C# and .NET (Core / 6+).

• Building and maintaining RESTful APIs and microservices with ASP.NET Core.

• Ensuring code quality through rigorous testing (unit, integration) and CI/CD pipelines (Azure DevOps, GitHub Actions).

• Collaborating closely with Frontend Developers, Product Owners, and DevOps engineers to deliver seamless digital solutions.

• Optimizing applications for performance, security, and scalability.

• Troubleshooting and debugging production issues to maintain high system availability.

• (For Senior profiles) Mentoring junior team members, driving technical architecture decisions, and championing best development practices.

Profile & Technical Skills

• Strong experience in C# and the .NET ecosystem (.NET Core / .NET 6+, ASP.NET Core, Entity Framework).

• Solid understanding of relational and non-relational databases (e.g., SQL Server, PostgreSQL, Cosmos DB).

• Familiarity with RESTful APIs, microservices architecture, and design patterns (SOLID, Clean Architecture, DDD).

• Experience with Azure (App Services, Functions, Service Bus) and containerization (Docker, Kubernetes) is a strong asset.

• Good understanding of Git, CI/CD tools, and agile methodologies (Scrum/Kanban).

• Excellent problem-solving skills and a strong team spirit.

• Language: Professional fluency in English. Knowledge of French or Dutch is a plus.

Why Smile?

• Proximity Management: Our management by peers fosters open dialogue and the implementation of a tailored career path.

• Continuous Learning: Because the digital sector is in constant motion, Smile is committed to making you an expert in your field, thanks to a comprehensive training offer: access to an e-learning platform, financing of certifications, and knowledge-sharing tools.

• Vibrant Culture: Your year will be animated by group and agency events: annual convention, participation in trade fairs, summer party, and formal & informal afterworks.

The Next Steps

1. First Contact: A phone call to discuss your aspirations and what we can offer you.

2. Meeting: An opportunity to get to know each other and explore your professional background.

3. Business Interview: A discussion with one of our experts to assess your technical skills and define your goals.