C# Trading Systems Developer

Phaxis; New York (NY); On-site; USD 180,000 - 240,000; Full time

Job summary

Phaxis in New York is seeking a Senior C# Trading Systems Developer to join our engineering team and help build, enhance, and support high-performance trading systems and financial technology platforms. This hands-on role requires strong C#/.NET development experience and a background in trading, brokerage, capital markets, or other real-time financial systems.

You will design and maintain C#/.NET trading apps, optimize low-latency paths, and collaborate with traders, product teams, and other

Qualifications

• 5+ years of professional software development experience.
• Strong C# and .NET development experience.
• Experience building backend or distributed systems.
• Knowledge of REST APIs, microservices and event-driven architecture.
• Strong SQL/database experience (SQL Server or PostgreSQL).
• Experience with real-time/high-throughput systems.
• Git and modern software development practices.

Responsibilities

• Design, develop, and maintain C#/.NET trading apps and services.
• Build high-performance, low-latency trading services.
• Integrate with brokerage APIs, OMS/EMS, and market data feeds.
• Develop real-time data, order management, and trading workflows.
• Work with relational databases and optimize SQL queries.
• Troubleshoot production issues and improve reliability.
• Contribute to architecture and technical design discussions.
• Review code for security, performance, and maintainability.
• Develop automated tests and support CI/CD.
• Collaborate with traders, product teams, and engineers.
• Support production trading environments and incident response.

Skills

C# / .NET

Backend systems

REST / Microservices

SQL databases

Real-time / high-throughput

Debugging / problem solving

Git / DevOps

CI/CD

Tools

Kafka

RabbitMQ

Redis

Azure

AWS

Docker / Kubernetes

CI/CD tooling

FIX Protocol

Job description

We are seeking a Senior C# Trading Systems Developer to join our engineering team and help build, enhance, and support high-performance trading systems and financial technology platforms. This role is ideal for a hands-on engineer with strong C#/.NET development experience and a background working with trading, brokerage, capital markets, or other real-time financial systems.

Responsibilities

Salary is 180k to 240k + bonus

We are seeking a Senior C# Trading Systems Developer to join our engineering team and help build, enhance, and support high-performance trading systems and financial technology platforms. This role is ideal for a hands-on engineer with strong C#/.NET development experience and a background working with trading, brokerage, capital markets, or other real-time financial systems.

• Design, develop, and maintain C#/.NET trading applications and backend services.
• Build high-performance, low-latency services supporting trading and order execution.
• Integrate with brokerage APIs, market data providers, OMS/EMS platforms, and other financial systems.
• Develop real-time services for market data, order management, execution, and trading workflows.
• Work with relational databases and optimize SQL queries and data access.
• Troubleshoot production issues and improve system performance, reliability, and scalability.
• Participate in architecture and technical design decisions.
• Review code and implement best practices for security, performance, and maintainability.
• Develop automated tests and support CI/CD processes.
• Collaborate with traders, business stakeholders, product teams, and other engineers.
• Support production trading environments and respond to time-sensitive technical issues.

Required Qualifications

• 5+ years of professional software development experience.
• Strong C# and .NET experience.
• Experience building backend or distributed systems.
• Strong understanding of REST APIs, microservices, and event-driven architecture.
• Strong SQL/database experience, preferably SQL Server or PostgreSQL.
• Experience working with real-time or high-throughput systems.
• Strong debugging, problem-solving, and system-design skills.
• Experience with Git and modern software development practices.

Financial/Trading Experience

Strong preference for candidates with experience in:

• Electronic trading platforms
• Brokerage systems
• Capital markets
• Hedge funds or asset management
• Order Management Systems (OMS)
• Execution Management Systems (EMS)
• Market data
• Trading APIs
• FIX Protocol
• Equities, options, futures, or other financial instruments

Nice to Have

• FIX Protocol
• WebSockets
• Kafka, RabbitMQ, or other messaging platforms
• Redis
• Azure or AWS
• Docker/Kubernetes
• CI/CD
• Low-latency/high-frequency trading systems
• Experience with trading algorithms or execution workflows