Senior Software Engineer (.NET)

Summary:

We are looking for a Senior .NET Engineer to help shape and scale TopstepX, our core trading platform. In this role, you will play a key part in designing, building, and operating the backend systems that power trading, market data, and brokerage integrations, with a focus on performance, reliability, and long-term platform health.

You will work primarily in C#/.NET, building cloud-native microservices that support high-throughput, low-latency workloads. Beyond shipping features, you will influence backend architecture, establish engineering patterns used across teams, and help ensure the platform can scale safely as usage and complexity grow.

This role is well suited for an engineer who enjoys owning systems end-to-end, thinking deeply about distributed systems and real-time data, and balancing technical rigor with practical business constraints. You will collaborate closely with product and design, mentor other engineers, and help define what “excellent” looks like for backend engineering. Join us and help define what technical excellence looks like at Topstep.

Key Responsibilities 

• Partner with the technical lead and architect to lead the implementation of Trading Platform projects.
• Deliver backend features end‑to‑end in C#/.NET, from design through production, with accountability for performance and availability.
• Contribute to shared patterns for .NET service design, API contracts, and performance practices.
• Partner with product/design to translate partner and trader needs into maintainable technical solutions.
• Build and operate cloud‑native services with a focus on safe deployments and operational simplicity.
• Improve developer experience, system performance, or deployment reliability through targeted technical initiatives.
• Mentor engineers on best practices, production ownership, and maintainable service design.
• Embed testing, monitoring, and operational thinking into feature delivery.
• Ensure automated test coverage across unit and integration layers; add end‑to‑end where it delivers a strong signal.

Required Qualifications and Key Competencies

• 5+ years building and operating production backend systems with user‑facing APIs; demonstrated impact on system scalability or reliability.
• Strong .NET (ASP.NET, DI, async/await, performance basics) experience shipping production services.
• Solid database fundamentals with PostgreSQL or SQL Server; schema design, migrations, and query optimization.
• Experience designing service boundaries, API versioning, and event‑driven patterns in a microservices or modular architecture.
• Production ownership mindset: metrics, logging, tracing, on‑call participation, and debugging in live systems.
• Experience with real‑time or async messaging (Redis, NATS, Kafka, etc.) OR real‑time comms (SignalR/WebSockets).
• Practical testing strategies across unit and integration boundaries.
• Clear technical communication; able to explain trade‑offs and collaborate with product/engineering partners.
• Comfortable balancing long‑term architecture with near‑term business needs.

Nice to Have

• Kubernetes experience (EKS or equivalent), Helm, or GitOps (ArgoCD) tooling.
• Distributed tracing and performance tuning in multi‑service systems.
• Incident leadership (RCA, remediation follow‑ups).
• Previous work in compliance‑constrained environments.
• General knowledge of financial markets and futures trading.

Company Culture & Perks

• Topstep is an engaging working environment which ranges from fully remote to hybrid. We foster a culture of collaboration with cameras on during meetings and a robust Slack environment for communication. 
• Seven Company-paid Holidays and generous Family Leave. Paid time off is front-loaded. 
• Competitive 401(k) matching, health, dental, and vision insurance is offered for full time employees.
• Vacations are encouraged with a bonus for taking 5 consecutive days. Employee referrals are bonused. Topstep offers a food and groceries budget and contributes towards health and wellness.

New Hire Base Salary Range

• $175,000-$210,000.
• Bonus: This position is eligible for a performance-based bonus as provided by the plan terms and governing documents.
• The compensation offered will take into account internal compensation structure and may vary depending on the candidate's geographic region, job-related knowledge, skills, and experience among other factors.

Equal Opportunity Employer

Topstep is an Equal Opportunity Employer. We are committed to fostering an inclusive environment where all employees and applicants are valued. All qualified candidates will receive consideration for employment without regard to race, color, religion, gender, gender identity or expression, sexual orientation, national origin, age, disability, or veteran status, in compliance with applicable federal, state, and local laws.

Interested in the role? Apply today with your resume and cover letter!

At this time immigration sponsorship is not available for this position (including H-1B, STEM OPT training plans, etc.).