Backend Software Engineer (.NET)

Agreement type: Full-time remote position, 40 hours per week,

Contractor agreement with Mission.

Our company description

Mission.dev is the next-gen staffing platform for software talent.

We help you find, evaluate, and manage top software talent (contractors or direct hires) faster, smarter, and more efficiently.

Powered by AI. Backed by real humans.

About the Client

This global SaaS provider develops a physical security workforce management platform used by thousands of organizations worldwide. The software acts as a unified system of record for security operations, offering integrated solutions for incident reporting, mobile patrols, and back-office functions such as scheduling and payroll. The platform helps security teams protect people and respond to incidents more efficiently by providing essential tools for field personnel and supervisors within a complex, mission-critical environment.

About the Role

As a Backend Software Engineer, you will take ownership of the services powering a mission-critical field operations platform. You will contribute to a modern microservices architecture built on the latest .NET standards while maintaining a stable, high-traffic legacy system. Working within a cross-functional squad, you will be responsible for the full lifecycle of backend features, from initial refinement to operational maintenance. This role requires independent execution, accountability for feature outcomes, and a commitment to improving code quality and system reliability across diverse codebases to support real-time field operations.

What You’ll Do

• Deliver complete backend features end-to-end, including implementation, testing, and database migrations for high-availability services.
• Build and maintain HTTP APIs and business logic across both modern microservices and established legacy applications.
• Design components using Clean Architecture and CQRS patterns to ensure reliability, performance, and scalability.
• Model relational data and optimize complex queries to maintain high performance in SQL Server environments.
• Conduct thorough code and schema reviews to ensure security, maintainability, and adherence to established architectural patterns.
• Manage the full operational lifecycle of owned services, including incident response and the implementation of regression tests.
• Leverage AI-assisted development tools to accelerate refactoring, test generation, and code comprehension across large codebases.
• Overlap at least 4 hours with CET and 4 hours with EST during working hours.

What You Bring

• 3+ years of professional experience in backend development using C# and .NET.
• Proficiency in building HTTP APIs with ASP.NET Core Web API, including dependency injection.
• Strong experience in relational data modeling and writing optimized T-SQL for SQL Server.
• Experience managing database migrations within a production environment.
• Proven ability to maintain and update large-scale legacy .NET Framework applications.
• Experience writing comprehensive unit and API integration tests.
• Familiarity with Git and working in an Agile development environment.

Nice to Haves

• Experience with Entity Framework Core for data persistence.
• Familiarity with CQRS, Clean Architecture, and microservices patterns.
• Experience using Docker and Docker Compose for local development environments.
• Knowledge of NATS or similar message-queueing systems for event-driven architectures.
• Experience incrementally migrating legacy functionality to modern service-oriented architectures.
• Bilingual proficiency in French.