Top C# Jobs

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

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.

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.

Design, implement, and maintain C++ and Python software for cross-platform, distributed real-time systems. Contribute to system architecture, APIs/messaging (gRPC/REST/ZeroMQ), CI/CD, automated testing, and integration of third-party simulation and hardware. Debug threading/timing issues and improve development workflows.

Lead architecture and implementation of high-performance C++ and Python systems, integrate distributed systems and simulation tools, own CI/CD pipelines, debug real-time multi-threaded systems, mentor engineers, and drive end-to-end integration across simulation and operational platforms.

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, implement, and maintain C++ and Python software for cross-platform, distributed real-time systems. Integrate third-party software/hardware and simulation tools, develop APIs/messaging (gRPC/REST/ZeroMQ), debug threading/timing issues, and improve CI/CD pipelines with Docker, CMake, Conan, and GitLab CI while practicing test-driven development and collaboration.

Lead design and integration of high-performance C++ and Python systems across distributed, real-time environments. Own CI/CD, containerization, build tooling, messaging/APIs, and debugging. Drive end-to-end integration, mentor engineers, set technical direction, and evaluate technologies to improve system performance and stability in autonomy and simulation domains.

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.

Design and develop low latency, high-performance trading systems. Optimize code and solutions for hardware efficiency, ensuring seamless application integration.

The Senior Software Engineer will develop scalable software frameworks, mentor junior engineers, and collaborate on design and feature development for web applications using diverse technologies.

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

The role involves designing, developing, and testing C++ applications for trading systems, collaborating with traders, and ensuring application reliability.

As a Software Engineer, you will design, develop, and deliver high-quality software, contribute to code reviews, monitor application performance, and ensure maintainability and consistency across products.

As a Software Development Engineer, you will create high-performance Linux software components, ensure system reliability, collaborate with teams, and design security features for containers in cloud environments.

Lead design, development, deployment, and maintenance of low-latency, cloud-based ad-serving systems in C++; mentor junior engineers, perform code reviews, optimize algorithms, work with Snowflake and Aerospike, collaborate with stakeholders, and support troubleshooting and operational duties including variable schedules.

Lead design, development, and support of high-performance C++ ad decisioning and delivery systems. Drive distributed system architecture, mentor engineers, collaborate with global teams, ensure scalability, reliability, integration, and production support.

The Sr. Software Engineer will design and optimize ad delivery systems, implement solutions on AWS, and provide technical leadership while mentoring junior engineers.

The Lead Software Engineer will build and maintain a high-performance video Ad Server, overseeing the software development lifecycle and mentoring a team.

The Software Engineer Principal will design, build, and support privileged access management solutions, focusing on CyberArk while mentoring others and improving operational resilience.

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

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

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.

Build and scale Buyercloud ad-serving systems that process billions of auctions daily. Design data- and model-driven features, optimize performance and cost, extend observability, participate in on-call rotations, produce documentation and playbooks, and support production incidents.

Design, implement, test, and deploy high-performance C++ APIs exposing a mortgage analytics quantitative library for interest rate modeling, prepayment/default analysis, derivative valuation, hedging, and forecasting. Improve performance, reliability, and usability of the library and collaborate with business, model development, validation, and IT teams.