Medior Backend .NET Developer

Mission Overview:

As part of the development of core business applications, we are seeking a Medior Backend .NET Developer for a consultancy mission at a client site representing Keystone Solutions. You will be hired by Keystone Solutions to work on diverse client projects, allowing you to tackle technical and strategic challenges in a dynamic consultancy environment.

Key Responsibilities:

• Understand and interpret UML and BPMN models.
• Know, use, and manage SQL Server databases from version 2016 to 2025.
• Know, use, and manage an ORACLE database from version 19.
• Apply design patterns based on architect recommendations.
• Develop REST services using .NET Framework and .NET 8 and above.
• Develop interfaces in ASP.NET WebForms / MVC, .NET 4.5 and above.
• Develop in XML and JSON.
• Know and use W3C standards.
• Know and use WebAPI, WCF REST, WCF, and Web Services.
• Know and use Azure DevOps with GIT and TFVC.
• Practical knowledge of Redgate tools is a plus.
• Know and use Entity Framework Core.

Additional Skills Desired:

• Ability to develop maintainable, high-performance code that adheres to team development standards.
• Experience in corrective and evolutionary maintenance of existing applications.
• Knowledge of SOLID principles and best practices in object-oriented development.
• Experience in writing and executing unit tests.
• Ability to diagnose and resolve technical incidents.
• Experience working in an Agile (Scrum) environment.

Expected Qualities:

• Autonomy in carrying out assigned developments.
• Analytical and problem-solving mindset.
• Ability to collaborate effectively with analysts, architects, and other developers.
• Good communication skills and a sense of teamwork.
• Rigorous, proactive, and quality-oriented.

Language Requirement:

The service in which the person will be integrated is predominantly French-speaking. Therefore, it is essential that the candidate is fluent in French.

If you are ready to tackle technical and strategic challenges in a dynamic consultancy environment, apply today at Keystone Solutions Career Portal.

Duration: 01/10/2026 - 31/12/2026 3 months • (full time)

Skills required:

• .Net - Level: Confirmed - Most recent: This year
• .NET Core - Level: Confirmed - Most recent: This year
• Agile - Level: Confirmed - Most recent: Any time
• Azure DevOps - Level: Confirmed - Most recent: This year
• Entity Framework Core - Level: Confirmed - Most recent: Any time
• GIT - Level: Confirmed - Most recent: 1 to 3 years ago
• JSON - Level: Confirmed - Most recent: This year
• RESTful API - Level: Confirmed - Most recent: 1 to 3 years ago
• Scrum - Level: Confirmed - Most recent: This year
• Soap API - Level: Nice to have - Most recent: Any time
• SOLID - Level: Confirmed - Most recent: Any time
• Sprint - Level: Confirmed - Most recent: Any time
• UML - Level: Nice to have - Most recent: Any time
• Visual Studio - Level: Confirmed - Most recent: 1 to 3 years ago
• XML - Level: Confirmed - Most recent: Any time

Language requirements:

Dutch
Level Passive knowledge
English
Level Passive knowledge
French
Level Native