Senior .NET Backend Developer

About the role

We are seeking an experienced Senior .NET Backend Developer to join our dynamic technical team in Luxembourg. You will work autonomously on existing business‑critical applications, delivering reliable, high‑performance solutions within an Agile environment.

Key responsibilities

• Develop, maintain, and enhance backend applications using C# and VB.NET.
• Design, build, and support REST APIs, SOAP web services, and enterprise integrations.
• Translate functional and technical requirements into robust code.
• Troubleshoot, refactor, and improve legacy modules.
• Ensure code quality through automated testing, code reviews, and secure development practices.
• Produce and keep up‑to‑date technical documentation.
• Collaborate with Business Analysts, QA, DevOps, and cross‑functional engineering teams.
• Participate actively in Agile ceremonies throughout the software development lifecycle.

Required profile

• Hands‑on developer passionate about backend engineering.
• Comfortable navigating complex existing codebases and building modern services.
• Self‑motivated yet effective in a collaborative team setting.
• Solution‑oriented with a strong focus on software quality and performance.
• Excellent communicator able to bridge technical details with functional stakeholders.

Required skills

• C# and VB.NET (both .NET Framework and .NET Core).
• REST API and SOAP web service development.
• SQL Server, relational database design, Entity Framework (or similar ORM).
• Authentication and authorization protocols (OAuth2, JWT).
• Asynchronous programming, multithreading, high‑concurrency patterns.
• Microsoft development tools: Visual Studio, Azure DevOps, Git, CI/CD pipelines.
• Agile/Scrum delivery experience.
• Message brokers and queuing (RabbitMQ, Azure Service Bus, Hangfire, MassTransit) – nice to have.
• Knowledge of Java or COBOL for legacy system bridging – nice to have.