Top Senior C# Jobs

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.

Lead development of a distributed, multi-asset Order Management System (OMS): design and implement core OMS infrastructure (workflow engine, pipeline, caching, event distribution), build automated deployment, improve legacy systems, ensure low-latency, high-availability, and support production stability while mentoring teams and evaluating vendor/architectural solutions.

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.

Lead development and design for global credit-card authorization systems. Create technical designs, implement complex features in C, write C++ unit tests (Google Test), define interfaces, improve CI/CD and development processes, lead code reviews, mentor junior engineers, and collaborate with product and other technical leads.

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.

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

Lead development of core client systems and engine-level infrastructure in Unity/C#. Diagnose and fix cross-cutting performance issues, upgrade third-party SDKs, evolve build tooling, produce design docs, scope multi-week infrastructure initiatives, mentor engineers, and drive profiling, optimization, and architecture changes to enable future features.

Design and implement high-performance GPU-accelerated software using C++ and CUDA. Develop CUDA kernels for signal and image processing, profile and optimize GPU applications, integrate with hardware (FPGAs, SoCs), collaborate with cross-functional teams, and apply DevSecOps/CI-CD practices to deliver production-quality defense systems.

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.

The Senior Software Engineer develops and maintains Sports Trading applications using .NET and SQL Server, enhancing existing functions and providing technical guidance.

Design, implement, and optimize high-performance C++ APIs exposing a mortgage analytics library for interest rate modeling, prepayment/default analysis, derivative valuation, hedging, and forecasting. Collaborate with business, model development, validation, and IT; improve library performance, safety, reliability, and usability; deploy and test production code.

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.

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 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 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.

Lead design, develop, test, and operate ultra-low-latency C++ trading connectivity and risk modules on Unix/Linux. Integrate FPGA pipelines with C++ for deterministic performance, automate remediation, establish latency/throughput/resiliency tests, and drive AI-assisted engineering adoption across the team.

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.

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 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.

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.

Design and optimize high-performance C++/CUDA libraries for GPU-based data processing. Improve multi-node GPU communication (UcxExchange), optimize Presto GPU query performance, and lead enhancements across Presto, Velox, and cuDF projects for efficient DataFrame and database acceleration.

Develop and optimize native C++ Android components for ground control stations, focusing on real-time telemetry, MAVLink communications, JNI boundaries, performance tuning, Qt/QML UI work, build systems, and field support to ensure reliable drone control across varied Android hardware.

Develop and maintain the Java client library and high-performance C/C++ server applications. Implement message parsers and feed handlers, optimize for extreme throughput and low latency, build tools for petabyte-scale processing, collaborate on build/deploy/CI practices, monitor uptime, and support smooth feature rollouts.

Implement and maintain the C# client library and high-performance C++ server applications. Build message parsers and feed handlers, optimize for millions of messages/second and nanosecond latency, develop petabyte-scale data tools, collaborate on build/deploy/CI/CD, monitoring, and ensure reliable feature rollouts.