C# / .NET Developer — API Identity authentication and authorization services

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tradezero americaEl Paso (TX)

Software Developers Computer Systems Design Services

SENIORITY

Senior

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About the role

C# / .NET Developer — API Identity authentication and authorization services (Mid-Level)

About the Role: We are looking for a mid-level C# / .NET developer to build and maintain high-performance API services that power our trading platform. You will work on various .NET API services other across the platform, specifically around our identity authorization and authentication API. This is a backend-focused role. You will work with Redis and relational databases to deliver scalable and reliable APIs in a production trading environment. Strong .NET fundamentals and comfort with distributed systems are important. What You'll Work On

Cross-service features — API services using SQL (PostgreSQL or SQL Server) and Redis, across the broader platform
Redis-backed data access — Reading and serving cached data snapshots with low latency; session and user-state management across data servers
API platform patterns — Building on our internal REST server framework: dual-port public/private hosting, Swagger documentation, compression, CORS, and standardized error handling

Responsibilities:

Design, implement, and maintain REST API endpoints in C# / ASP.NET Core (.NET 8+)
Experience with authorization and authentication best practices including OAuth 2.0, API keys, JWT tokens, MFA, key rotation, etc.
Integrate with Redis for caching, snapshots, and pub/sub patterns using Stack Exchange. Redis and related libraries
Write and optimize SQL queries and stored procedures against PostgreSQL or SQL Server as needed
Add Swagger/OpenAPI documentation and follow established API conventions
Tune performance for high-throughput, low-latency scenarios (thread pool configuration, connection pooling, async patterns)
Participate in code reviews, troubleshooting production issues, and iterative feature delivery

Required Qualifications:

3–5 years of professional experience with C# and .NET (ASP.NET Core)
Solid understanding of REST API design, HTTP semantics, and API versioning practices
Comfort with async/await, dependency injection, and standard .NET service patterns
Experience with Redis — caching, key design, connection management, and basic pub/sub
Experience with relational databases — writing queries, understanding indexes, and working with PostgreSQL or SQL Server
Familiarity with Git, CI/CD pipelines, and deploying services to production

Nice to Have:

Experience with Polly or similar resilience libraries (retries, circuit breakers)
Experience with performance logging, observability, and production debugging under load

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