Top C# Jobs

Lead design, implementation, testing, and support of FreeWheel's high-scale video advertising platform. Own feature lifecycle, produce technical specs, write efficient code, integrate components, and maintain documentation. Provide production support, mentor junior engineers, collaborate with product and operations, and drive technical innovation and architectural decisions.

Design, customize, and maintain C++ applications in a Linux environment. Lead releases, collaborate with stakeholders and QA, mentor junior engineers, manage documentation, track performance metrics, and participate in design and peer-programming sessions. May work variable schedules including nights and weekends.

Design, build, and scale low-latency ad-serving systems and data/model-driven features. Optimize algorithms and architectures for performance and cloud cost, extend observability, participate in on-call rotations, and produce runbooks and documentation.

Leads the design, development, modernization, and support of high-performance, low-latency trading software using C++ and FIX. Integrates real-time market data, improves scalability and reliability, oversees testing, debugging, code reviews, deployment automation, documentation, and disaster recovery. Mentors engineering teams, collaborates with traders and analysts, provides technical leadership, and drives adoption of modern technologies and software development practices in a mission-critical trading environment.

Design, develop, and own high-performance C++ cloud-based ad-serving and distributed systems. Mentor junior engineers, collaborate with stakeholders, optimize algorithms, deploy and maintain Linux-based services, use Snowflake and Aerospike, review code, and improve system reliability and scalability.

Design, build, and maintain scalable backend and distributed systems while operating in AI-augmented workflows. Validate AI-generated outputs, contribute to architecture and system evolution, produce technical documentation and prompts, mentor peers, and collaborate with Product, UX, and Engineering teams to ensure reliability, observability, and engineering quality.

The Market Data Engineer will design and implement high-performance market data systems, focusing on trading infrastructure, performance optimization, and system resiliency.

As a Full Stack Engineer, you'll develop online services features using C#, React, and ensure best practices in software development. Collaboration with global teams is key.

The role involves building and supporting production-level trading systems in C++ for credit and rates products, collaborating with traders and quantitative researchers.

Leads development of secure, scalable, high-performance, low-latency trading applications and user interfaces for global trading desks. Designs, codes, tests, reviews, debugs, and improves software across the SDLC. Drives adoption of responsible AI-assisted engineering practices, automates recurring remediation, evaluates vendor technologies, and mentors teams on secure, resilient delivery.

Lead architecture and implementation of high-performance C++ and Python systems, integrate distributed and real-time systems, own CI/CD and build tooling, debug multi-threaded systems, guide cross-team integration and mentor engineers, and evaluate new technologies to improve simulation and autonomy platforms.

Design, develop, and field high-performance Ground Control Station and C2 software using C++/Qt/QML and QGroundControl. Lead architecture and technical direction, mentor engineers, define APIs/ICDs, debug integration/latency issues, support field tests, implement post-mission debrief tools, and ensure interoperability with C2 standards.

Lead architecture and implementation of high-performance C++ and Python systems, integrate distributed systems and hardware/software, manage CI/CD pipelines, debug and optimize real-time multi-threaded systems, guide end-to-end integration and verification, mentor engineers, and evaluate new technologies to improve system performance.

Software Engineers at Citadel develop, maintain, and support high-performance trading platforms, focusing on custom software solutions and system stability.

Develop and enhance performance-critical C++ applications for ultra-low latency trading systems, collaborating across teams to analyze and optimize performance.

Leads software engineering projects for a global index business platform within investment banking. Develops, tests, reviews, and debugs secure Python and TypeScript production code on the Athena trading and risk platform. Collaborates with quantitative research, trading, sales, structuring, and operations teams to deliver business solutions. Drives responsible adoption and governance of AI-assisted engineering tools, improves SDLC automation, influences platform design, and serves as a technical subject matter expert.

Responsibilities include developing scalable server-side features, optimizing performance, and collaborating with teams to enhance online services for games.

Develop scalable server-side features, online services, and collaborate with teams. Requires C#, .NET expertise and experience in distributed systems.

Lead design and delivery of ultra-low-latency electronic trading systems (Smart Order Router, Matching Engine, Market Access, Risk Management). Develop and enhance trading strategies, ensure scalability and reliability, conduct code reviews and testing, and collaborate with cross-functional teams following Agile practices.

Lead engineering role building and evolving the Sigma data-visualization platform: develop C++/Rust->WASM engine, integrate Apache Arrow, build TypeScript/React (Next.js) front-end, extend data adapters, tune WASM performance, ensure secure high-quality production code, drive architecture decisions, evaluate vendors, and lead engineering communities to improve operational stability.

Lead technical design and deliver secure, scalable C#/.NET software for trading systems. Drive architecture, coding, code review, automation, resiliency, CI/CD, and adoption of AI-assisted engineering practices while mentoring teams and engaging vendors.

Join an on-site Chicago team building high-performance C++ trading systems. Contribute to design, development, testing, profiling, and troubleshooting. Collaborate with traders and senior engineers, receive mentorship, and gain exposure to the full lifecycle of low-latency trading platform development.

Join an on-site Chicago team building high-performance C++ trading systems. Design, develop, test, profile, and troubleshoot low-latency applications while collaborating with traders and senior engineers. Receive mentorship, training on markets, and exposure to production lifecycle and performance tuning.

Design, implement, and maintain C++ components for a global electronic trading platform. Collaborate on system design, perform code reviews, troubleshoot production issues, and improve system stability while participating across the software development lifecycle.

Software Engineers at Citadel develop software solutions for trading platforms, optimizing performance and functionality, and support trading activities.