Senior .NET Developer / Architect (Freelance) – 12 Month Project
Location: Brussels, Belgium (2 days on-site)
Duration: 12 months
Start date: ASAP (client can wait up to 4 weeks)
Language: English required, French is a plus
Client: Software / SaaS company
Project Overview
Our client, a Brussels-based software company, is looking for a Senior .NET Developer with hands-on architecture experience to join their internal development team on a 12-month freelance assignment.
The role has opened due to an internal team shift, creating a need for a senior expert who can support the team while helping modernize the existing system architecture.
You will work on an internal SaaS solution with a strong focus on API development and data-driven applications, helping the team transition parts of the system toward a cloud-based environment (Azure).
In addition to development and architectural work, the role includes coaching and mentoring junior and medior developers.
Key Responsibilities
Development & Architecture
Design and develop REST APIs using .NET technologies
Improve and refactor existing system architecture (reducing technical debt and “spaghetti” architecture)
Contribute to the migration from on-premise infrastructure toward cloud environments (Azure)
Work on an API-driven application connected to a SQL database
Ensure scalable and maintainable software architecture
Data & Integration
Work closely with data structures and database systems
Contribute to data processing, structuring, and presentation layers
Ensure efficient API integration with internal systems
Team Support & Coaching
Mentor and coach junior and medior developers
Share best practices in software architecture and development
Support knowledge sharing within a small collaborative development team
Required Skills & Experience
5–7+ years of experience with .NET development
Strong experience with REST API development
Hands-on architecture experience
Experience with SQL databases
Strong analytical skills, particularly around data-driven systems
Experience with Azure Cloud
Ability to work in small, collaborative teams
Strong communication and mentoring skills
Nice to Have
Experience with DevOps practices or tooling
Experience with cloud migrations
French language skills
Work Environment
Small development team with strong collaboration
Hybrid work model: 2 days on-site in Brussels
Opportunity to impact architecture decisions and technical direction