Senior Software Engineer

Topstep is looking for a Senior Software Engineer to own and evolve critical components of our trading platform. In this role, you'll design and build systems that power real-time trading and market data delivery, ensuring reliability and scalability as the platform grows.

Responsibilities:

• Design and build services and APIs that power core trading platform capabilities
• Own features end-to-end, from technical design through production deployment, monitoring, and iteration
• Collaborate with product and design to translate user needs into scalable, maintainable technical solutions
• Contribute to system architecture decisions, establishing patterns and practices that other teams can follow
• Write clean, well-tested code with strong focus on reliability, performance, and operational excellence
• Participate in on-call rotations, respond to incidents, and drive continuous improvement of system reliability
• Build and maintain observability into your systems through metrics, logging, and distributed tracing
• Occasionally work across the stack, contributing to the React/TypeScript frontend as features require
• Mentor engineers through code reviews, pairing sessions, and sharing knowledge about system design and best practices
• Balance technical debt against feature delivery, making thoughtful trade-offs based on business priorities and technical constraints
• Strengthen engineering culture through documentation, tooling improvements, and process refinements

Requirements:

• 5 + years of software engineering experience building and shipping production systems at scale
• Strong proficiency in C# and the .NET ecosystem, with experience building production services
• Experience designing service boundaries and API versioning in a microservices or modular architecture
• Experience building distributed, high-availability systems, including asynchronous, event-driven communication between services (e.g., message queues, pub/sub, or streaming)
• Solid database experience with PostgreSQL or SQL Server, including schema design, query optimization, and transactional behavior
• Experience with observability tools and distributed tracing in production environments
• Proven track record of owning production systems, including debugging and incident response
• Experience with container technologies (Docker) and cloud platforms (AWS)
• Strong testing mindset with practical experience across unit, integration, and system testing
• Excellent problem-solving skills, with the ability to debug complex issues across multiple systems
• Clear communication, including the ability to explain technical trade-offs to both engineering and product stakeholders
• Kubernetes experience (EKS or equivalent), Helm, or GitOps (ArgoCD) tooling
• Experience with React, TypeScript, or other modern frontend frameworks
• Experience with real-time client comms (SignalR/WebSockets)
• Background in high-throughput, low-latency systems, including performance tuning across multiple services
• Incident leadership (RCA, remediation follow-ups)
• Previous work in financial services, fintech, or other compliance-regulated environments
• Understanding of trading systems, market data, or brokerage operations