Top C# Jobs in Chicago, IL

The C# / .NET Developer will design and maintain middleware applications, build Shopify integrations, and support a mobile app backend in a remote work environment.

Design and evaluate performance engineering tasks for AI training/evaluation. Optimize runtime, compilers, memory, CPU/GPU and concurrency. Produce documented solutions, evaluate AI-generated code, and build evaluation frameworks and scoring rubrics while collaborating with researchers and SMEs.

Design, implement, and maintain low-latency C++ applications for trading strategy execution, optimizing performance, and collaborating with traders and engineers.

Develop user interface components for ArcGIS Pro using C# and WPF, work in an agile team, and design software solutions for raster and imagery processing.

PrivateID seeks a Principal C++ Engineer with at least 10 years of experience to lead complex systems and scale their platform in a remote-first environment.

Seeking a Senior Software Engineer to design and implement multimedia data systems using C# and .NET Core. Responsibilities involve developing high-performance applications, collaborating with teams, and driving engineering excellence in an Agile environment.

Build and maintain scalable, cloud-native APIs using .NET. Enhance core platform components, lead architecture and testing discussions, optimize telemetry and performance, collaborate cross-functionally, conduct code reviews, and mentor team members.

You will develop and maintain components of the LLVM based toolchain, collaborating with the community while ensuring platform-specific optimizations and tests.

Design, develop, test, and maintain scalable C#/.NET applications and RESTful APIs. Build data-driven platforms, implement CI/CD and DevOps practices, deploy containerized apps (Docker/Kubernetes) on AWS, troubleshoot production issues, and collaborate on architecture, code reviews, and observability improvements.

Evaluate AI coding-agent interactions for usefulness, correctness, engineering judgment, reasoning quality, and overall developer experience. Provide rigorous, opinionated feedback, distinguish response-quality levels, and help define standards for excellent interactions with tools such as OpenAI Codex, Claude Code, and Cursor. The role requires deep software engineering experience, familiarity with AI-assisted development workflows, and the ability to assess code and explanations without reviewing every line.

Remote backend C# developer to build and optimize a high-load spot-exchange matching engine. Improve performance and API throughput, implement business features, write unit and integration tests, work with .NET Core and PostgreSQL on AWS, and apply multithreading, async, and distributed systems concepts.

Contract .NET developer/consultant role requiring 5+ years experience building web applications using C#, .NET, Entity Framework, SQL Server, LINQ, WCF, MVVM/MVC, and JavaScript frameworks (JSRender, Angular, Node, jQuery, HTML5). 6+ month contract; rate DOE.

Join the UI team for a 10-week summer internship to design, build, test, and maintain real-time C# .NET desktop trading applications. Collaborate with traders, quants, and engineers, implement unit and integration tests, evaluate UI technologies, and participate in Agile/Scrum and application support processes. Interns own a project and present outcomes at program end.

Work on high-performance, low-latency C++ systems for trading: maintain core systems, implement lower-risk features, execute individual projects, and collaborate with Quant and Trading. Focus areas include concurrency, networking, profiling, and performance tuning while supporting multithreaded, asynchronous, and distributed architectures.

10-week C++ software engineering internship working on low-latency, multithreaded, distributed trading systems. Interns design, implement, and maintain components, collaborate with Quant and Trading, and deliver projects from ideation through production while using performance profiling, debugging tools, and modern C++ techniques.

As a Staff Software Engineer for Liquidity Management, you'll lead architectural decisions, mentor engineers, and drive platform development, focusing on scalable, reliable systems for treasury management in a fast-paced environment.

Lead technical direction for a major product domain, reduce architectural debt, mentor engineers, standardize AI-agent workflows, and design scalable backend solutions integrating LLMs and cloud services. Drive cross-team RFCs, cookbook standards, and adopt agentic AI tooling while balancing security, quality, and delivery.

Build, integrate, and stress-test full-stack applications and backend services that leverage advanced AI models. Develop production APIs, front-end features, databases, and cloud infrastructure; troubleshoot integrations; prototype rapidly and deliver high-quality code and documentation in fast-moving environments.

The Back End Software Engineer will design and build scalable services for a SaaS platform, collaborate with teams, and contribute to quality code and architecture discussions.

Design, build, test, and support web and client-server applications; lead custom SharePoint intranet development; implement front-end features using C#/.NET and JavaScript frameworks; optimize performance and scalability; produce technical specifications, documentation, QA, and user training; maintain .NET certifications.

Lead design and global rollout of a high-performance core market data and execution platform. Implement and optimize low-latency market data ingestion, normalization, distribution, and execution components in modern C++. Own deployment, monitoring, profiling, and production optimization while collaborating closely with quants and technical traders to enable systematic pricing and trading strategies.

Lead development of high-performance C++ trading systems and core platform components, build and optimize exchange connectivity (market data and order flow), implement trading algorithms, improve stability and observability, troubleshoot production issues, and collaborate closely with quants and traders to iterate on design and deployment.

The role involves using C++ for software development focusing on object-oriented principles, with projects on Linux and Windows operating systems. It requires strong debugging and testing skills, along with adaptability to new technologies.

The C++ Developer will engage in software development focusing heavily on C++ and object-oriented programming, primarily for Linux and Windows systems.

As a Sr. Software Engineer at Bloomerang, you will lead technical direction, mentor engineers, and enhance SaaS solutions while utilizing .NET and AI tools. You will ensure scalable, maintainable applications, advocate for Agile workflows, and focus on quality outcomes in software development.