Senior Backend .NET Developer

Mission Overview: Keystone Solutions is seeking a Senior Backend .NET Developer for a consultancy mission at a client site. In this role, you will be responsible for the development of core business applications, working on dynamic projects that offer a variety of challenges across different client environments. Key Responsibilities: Understand and interpret UML and BPMN models. Manage and utilize SQL Server databases from version 2016 to 2025. Manage and utilize Oracle databases 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. Work with XML and JSON. Utilize W3C standards. Work with WebAPI, WCF REST, WCF, and Web Services. Utilize Azure DevOps with GIT and TFVC. Practical knowledge of Redgate tools is a plus. Utilize Entity Framework Core. Additional Skills Required: Ability to analyze functional requirements and translate them into technical solutions in collaboration with Scrum and solution architects. 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. Participate in code reviews and continuous improvement initiatives. 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. Strong communication skills and a team-oriented approach. Rigorous, proactive, and quality-oriented. As a consultant at Keystone Solutions, you will experience turbo-charged learning and career growth opportunities while embodying our core values in every engagement. 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: Expert - Most recent: This year .NET Core - Level: Expert - Most recent: This year Agile - Level: Expert - Most recent: Any time ASP.NET - Level: Confirmed - Most recent: 1 to 3 years ago ASP.NET MVC - Level: Confirmed - Most recent: 1 to 3 years ago Azure DevOps - Level: Expert - Most recent: This year Entity Framework Core - Level: Expert - Most recent: This year GIT - Level: Expert - Most recent: 1 to 3 years ago JSON - Level: Expert - Most recent: This year RESTful API - Level: Expert - Most recent: 1 to 3 years ago Scrum - Level: Expert - Most recent: This year Soap API - Level: Nice to have - Most recent: Any time SOLID - Level: Expert - Most recent: This year Sprint - Level: Expert - Most recent: Any time UML - Level: Nice to have - Most recent: Any time Visual Studio - Level: Expert - Most recent: 1 to 3 years ago XML - Level: Expert - Most recent: Any time Language requirements: Dutch Level Passive knowledge English Level Passive knowledge French Level Native