Senior Fullstack Software Engineer (.NET & React)

About the role

Join Deloitte Luxembourg's Digital Factory, a multidisciplinary team of about 85 technology and financial experts. As a Senior Fullstack Software Engineer you will own end‑to‑end solutions, shape engineering practices, and mentor colleagues while delivering data‑intensive applications for major financial institutions.

Key responsibilities

• Architect, develop, and maintain full‑stack applications using C#/.NET, SQL Server and React, ensuring scalability, resilience and maintainability.
• Design high‑performance, data‑intensive APIs, processing workflows and integrations.
• Define and apply architectural patterns such as clean architecture, CQRS and event‑driven design.
• Build robust user interfaces with React, emphasizing component architecture and state management.
• Define, promote and enforce engineering standards, including code reviews, testing strategies and CI/CD pipelines.
• Own non‑functional requirements like performance, security and observability, and drive technical debt remediation.
• Mentor junior and mid‑level engineers, lead technical discussions and foster consensus.

Required profile

• Several years of experience delivering full‑stack solutions in a financial services context.
• Strong track record of technical leadership and architectural decision‑making.
• Ability to work collaboratively in an Agile, multidisciplinary environment.
• Commitment to continuous learning and knowledge sharing.

Required skills

• C# / .NET
• SQL Server
• React (JavaScript/TypeScript)
• Clean Architecture
• CQRS
• Event‑driven design
• CI/CD pipelines
• Unit, integration and end‑to‑end testing
• Performance monitoring, security and observability practices

What we offer

• Impactful work on data‑intensive applications for leading financial institutions.
• Clear technical career path toward Lead Engineer and Architect roles.
• Learning budget, internal tech talks and access to Deloitte’s global knowledge network.
• Flexible hybrid working model and a culture that values performance and wellbeing.