Technical Lead .NET – Application Modernization & Migration

ITS Group Benelux; Brussel Hoofdstad; On-site; EUR 90,000 - 120,000; Full time

Benefits offered by this job

Hospitalization insurance (partner/儿童含

Group insurance

Dental insurance (partner/children)

20 days statutory paid vacations

11 days recovery time work 38/40 per

Representation fee net per month.

Internet fee of € 40 per month.

Company car with national fuel card OR

Daily fee of 5.50€ net /day

Subscription GSM unlimited calls for

Training plan (e-learning - ITS charge

Job summary

ITS Group Benelux is seeking an experienced Technical Lead .NET to drive application modernization and migration for key public-sector clients. You will combine hands-on coding with architectural ownership, guiding a cross-functional team toward scalable, secure solutions using .NET Core and .NET 10.

You will mentor developers, ensure code quality, and translate business needs into robust designs while collaborating with analysts, portfolio architects and operations.

Qualifications

• Expertise in .NET development with leadership responsibilities.
• Strong hands-on C# and .NET Core experience.
• Experience with .NET 10 or newer versions.
• Expert knowledge of ASP.NET Web API and REST/Swagger.
• Secure development practices and OWASP awareness.

Responsibilities

• Provide technical leadership and mentoring to the development team.
• Remain hands-on with coding, feature development and bug resolution.
• Own the technical direction of the application's architecture.
• Design scalable, secure, maintainable solutions and modernize existing apps.
• Coordinate with analysts, developers, and Project Lead.

Skills

Expert .NET

C# & .NET Core

REST APIs

JWT/OAuth/OIDC

SQL Server

Git & Azure DevOps

Unit Testing

Secure coding

Design patterns

Performance tuning

Education

4+ years IT experience

Tools

ASP.NET Web API

Swagger/OpenAPI

.NET 10

Azure DevOps

Git

Job description

Technical Lead .NET – Application Modernization & Migration

Great assignments await you with our key account clients in rich and varied environments

Our client, a major public-sector organization, is looking for an experienced Technical Lead .NET to join a multidisciplinary team responsible for modernizing and migrating several business-critical applications.

The Technical Lead will combine hands-on software development with technical ownership, architecture alignment and coaching of the development team. The objective is to deliver scalable, secure, reliable and maintainable solutions using modern Microsoft technologies, including .NET 10.

This position requires a strong technical leader who remains actively involved in coding and can translate functional requirements into robust technical solutions.

As Technical Lead .NET, you will take responsibility for the technical quality and direction of the applications delivered by the team.

Your responsibilities will include:

• Provide technical leadership, guidance and mentoring to the development team.
• Remain actively involved in hands-on coding, feature development and bug resolution.
• Take technical ownership of the software systems managed by the application team.
• Design scalable, reliable, secure and maintainable solutions.
• Modernize and migrate existing applications toward .NET Core and .NET 10.
• Translate business and functional requirements into robust technical designs.
• Collaborate with functional analysts, business analysts, developers and the Project Lead.
• Work closely with portfolio architects and Infrastructure & Operations teams.
• Ensure compliance with architectural principles and development standards.
• Conduct code reviews and promote clean code, quality and development best practices.
• Define and maintain unit and integration-testing practices.
• Prepare technical documentation, infrastructure requests and release deliverables.
• Coordinate configuration changes and support deployment activities.
• Integrate security principles into application design and development.
• Monitor and optimize application performance, stability and maintainability.
• Lead the resolution of complex technical problems.
• Evaluate and integrate technologies aligned with business and architectural objectives.
• Contribute to a collaborative engineering culture focused on continuous improvement.

You have the following skills

Required technical expertise

• Expert experience in .NET development and technical leadership.
• Strong hands-on expertise in C# and .NET Core.
• Experience with .NET 10 or recent versions of modern .NET.
• Expert knowledge of ASP.NET Web API.
• Authentication and authorization using JWT, OAuth2, OpenID Connect, OIDC and claims.
• REST APIs and Swagger/OpenAPI.
• SQL Server.
• Git and Azure DevOps/DevOps Server.
• Unit and integration testing.
• OWASP principles and secure-development practices.
• Design patterns, clean code and development best practices.
• Understanding of networking and infrastructure concepts.
• Experience designing scalable and maintainable application architectures.
• Strong code-review, troubleshooting and performance-optimization capabilities.

Leadership and interpersonal skills

• Proven experience as a Technical Lead, Lead Developer or hands-on Solution Architect.
• Ability to coach, mentor and support developers.
• Strong analytical and technical decision-making skills.
• Ability to explain complex technical topics to technical and non-technical stakeholders.
• Collaborative mindset and experience working with cross-functional teams.
• Ability to align technical choices with business needs and strategic architecture.
• Resilience and adaptability in complex application environments.

Languages

• Fluent French or Dutch at C2 level.
• Very good command of English at C1 level.
• You have at least 4 years of professional experiences in IT
• If you are at least fluent in FR/ENG or NL/ENG it’s best
• You’re eager to learn, motivated and curious
• Let’s have a chat !

Advantages

• Hospitalization insurance (partner/children incl.)
• Group insurance
• Dental insurance (partner/children included)
• 20 days statutory paid vacations (legal vacations cumulated for 1 year of work)
• 11 days recovery time work 38/40 per year (= annual average: 1 day per 20 days worked) if the client asks you to work 8h/day
• Representation fee net per month.
• Internet fee of € 40 per month.
• Company car with national fuel card OR Public transport reimbursed OR mobility package.
• Daily fee of 5.50€ net /day provided.
• Subscription GSM unlimited calls for Belgium (ITS subscription)
• Training plan (e-learning - certification at ITS charge)
• Being a rather small team in BE (6 in back-office), we’re very close to each of our consultants and we differentiate ourselves trying to really take care of you and make you grow with us and within our different clients.
• Regular follow-up (every 3 to 6months depending on your needs/will)
• Regular teambuilding to meet-up and have fun (every 3 months more or less)
• Flexibility and trust
• Benefits of still being part to a bigger group (ITS Group) and having access to resources and of a larger team of Experts
• Co-optation system because sharing is caring!
• 1st pre-screening on the phone to discuss about your search and conditions and our first potential opportunities matching.
• Job descriptions sent and Teams meeting fixed with us (HR and Sales) to dig into your experience and the role.
• Package proposal so we all agree beforehand.
• Your CV is sent to the different clients you’ve agreed to, to find the best mission for you!

For more than 25 years, ITS Group has been a French ESN specializing in digital transformation, employing around 1,400 employees across 8 agencies in France and 1 in Belgium.

Our expertise: IT infrastructure & operations, cloud & managed services, mobility, workstations & networks, strategy, consulting & AMO, cybersecurity, development of business applications.

ITS Group places its CSR commitment at the heart of its concerns by developing sustainable and responsible digital technology and by promoting the professional and personal development of its employees.