Senior .NET Engineer / C++ / Fintech / Trading / Hybrid / Chicago, IL

This online brokerage and trading-technology firm that offers a professional-grade trading platform for retail and institutional traders alike. Their platform provides a customizable dashboard environment that lets users build their own layout — with flexible blocks for charts, quotes, option chains, and orders — so traders can tailor the interface to their workflow and trading style.

For retail investors, they aim to bring “pro-level” trading tools — including options trading and access to advanced charting and order execution — while keeping pricing accessible. For more advanced or professional traders (or firms), they also offer portfolio-margining, customized execution, clearing and custody options, and back-office support — making it a viable solution for sophisticated trading strategies and institutional operations.

They are looking for a highly skilled Senior .NET Engineer with strong experience in building high-performance, real-time applications within the fintech or trading domain. In this role, you will design, develop, and optimize mission-critical systems that support trading workflows, pricing engines, market data processing, and other financial operations. The ideal candidate brings a deep understanding of modern .NET development, strong C++ experience, and hands-on work with SQL databases in fast-paced, data-intensive environments.

Required Skills & Experience 

• 5–7+ years of professional software engineering experience
• Strong proficiency in C#, .NET Core, and API/service development
• Hands-on experience with C++ in performance-critical applications
• Strong SQL skills and experience working with relational databases (SQL Server, PostgreSQL, etc.)
• MUST HAVE experience in fintech, trading systems, market data, or financial services
• Solid understanding of multithreading, concurrency, and distributed system design
• Experience in real-time or low-latency application development is a strong plus

What You Will Be Doing Tech Breakdown:

• 30% maintenance
• 70% new development

Daily Responsibilities: 

• Design, develop, and maintain backend services and trading-related applications using C# and .NET Core
• Build high-performance components and low-latency modules in C++ to support pricing, execution, and market data processing
• Develop and optimize SQL database structures, queries, and stored procedures for large-scale financial datasets
• Collaborate with product managers, quantitative teams, and DevOps to deliver reliable and scalable trading systems
• Integrate with market data providers, order-routing systems, or financial APIs as needed
• Implement best practices for secure, compliant, and fault-tolerant fintech applications
• Troubleshoot performance bottlenecks and production issues within distributed, real-time environments
• Contribute to architecture decisions, code reviews, and continuous improvement initiatives

Office Location

• Chicago Loop, IL
• Hybrid
• 4 days onsite // 1 day WFH

The Offer

• $150-180K base

You will receive the following benefits:

• Medical Coverage
• Dental Coverage
• 401K
• PTO

Applicants must be currently authorized to work in the US on a full-time basis now and in the future.