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