C# / .NET Developer — API Services (Mid-Level)

C# / .NET Developer — API 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. This is a backend-focused role. You will work with Redis, relational databases, and message brokers to deliver low-latency, reliable APIs in a production trading environment. Prior trading or brokerage experience is helpful but not required; strong .NET fundamentals and comfort with distributed systems matter more. What You'll Work On • Cross-service features — API services using SQL (PostgreSQL or SQL Server), Redis, and pub/sub middleware 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 • Message-driven workflows — Publishing requests via RabbitMQ and integrating with downstream consumers • 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+) • Integrate with Redis for caching, snapshots, and pub/sub patterns using StackExchange.Redis and related libraries • Work with RabbitMQ (or similar brokers) for asynchronous messaging and event-driven workflows • Write and optimize SQL queries and stored procedures against PostgreSQL or SQL Server • 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 • Experience with message brokers — RabbitMQ, or comparable middleware (Kafka, Azure Service Bus, etc.) • Familiarity with Git, CI/CD pipelines, and deploying services to production Nice to Have • Experience in financial services • Familiarity with MessagePack or other binary serialization for performance-critical paths • Experience with Polly or similar resilience libraries (retries, circuit breakers) • Experience with performance logging, observability, and production debugging under load