Top Senior C# Jobs

Leads and develops a software engineering team while contributing hands-on to enterprise application design, coding, testing, code reviews, production support, and technical decisions. Builds scalable solutions using C#, ASP.NET, SQL Server, and modern web technologies; partners with product and business stakeholders; supports Agile delivery, CI/CD, troubleshooting, root cause analysis, and engineering best practices. The role also includes mentoring engineers, monitoring delivery and operational metrics, and driving continuous improvement.

Lead the design, development, testing, debugging, and maintenance of high-performance C++ software for Linux-based machine-control and commissioning systems. Own complex technical problems, contribute to architecture, lead design reviews, mentor engineers, and improve software quality and reliability. Collaborate with product, architecture, QA, and distributed engineering teams to deliver embedded and real-time solutions for earthmoving automation.

Develop and optimize low-latency C++ software on Linux for IBCS sensor integration and composite track processing. Implement RTI DDS middleware, process and correlate sensor and radar data, support Combat Identification logic, and integrate software with hardware interfaces and battle-management nodes. Collaborate in SAFe/Scrum environments using Jira and Confluence while troubleshooting concurrency, serialization, and network-latency issues.

Develop and optimize high-throughput C++ algorithms for remote sensor data exploitation, image analysis, detection, and tracking. Design software architectures, contribute to Agile teams and shared tools, and work with databases and Linux systems. The role requires strong object-oriented programming, data structures, concurrency, and performance optimization skills.

Develop and maintain .NET and C# web applications using MVC and IIS on Windows Server. Perform software testing, SQL stored procedure development, SDLC activities, defect tracking, technical documentation, and mentoring of junior personnel. Requires an active TS/SCI clearance with CI polygraph and eligibility for additional clearances.

Develop and maintain high-fidelity, real-time C++ simulation software for SpaceX flight systems and vehicles. Build simulation infrastructure and physics models, prototype designs, improve performance and reliability, and collaborate with engineering teams and simulation users to deliver new capabilities. The role requires strong software development, debugging, optimization, testing, distributed systems, networking, memory management, and physics knowledge.

Designs, builds, and owns production-grade full-stack services and UI features for Finastra’s Azure-hosted lending platform. Responsibilities include developing C#/.NET and Angular applications, REST APIs, background services, event-driven integrations, secure and testable code, and CI/CD pipelines. The role contributes to architecture, technical documentation, code reviews, and system operational readiness while mentoring engineers. Daily use of GitHub Copilot and AI agents is expected, with strong judgment applied to all generated output.

Leads the architecture, development, and delivery of a global equity derivatives pricing platform and RFQ workflow. Develops Java server and C# client features, designs REST-based solutions, maintains automated test suites, improves CI/CD pipelines, and supports deployment strategies. The role includes requirements refinement, architecture planning, proof-of-concepts, agile delivery, compliance, mentoring engineers, and collaboration with business and platform partners.

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

Develop and maintain scalable enterprise web applications using React, JavaScript or TypeScript, C#, and .NET. Build responsive interfaces, backend services, REST APIs, and microservice integrations. Design Azure cloud solutions, support CI/CD deployments, participate in architecture and code reviews, troubleshoot applications, and collaborate with stakeholders, QA, product owners, and developers in an Agile/Scrum environment.

Design, build, and maintain Stellar Core, the distributed system powering the Stellar blockchain. Responsibilities include developing scalable network components, improving peer-to-peer and processing performance, strengthening resilience and decentralization, investigating bottlenecks, authoring protocol specifications, and contributing to architecture, code reviews, and open-source engineering practices.

Design, build, and maintain Stellar Core, the distributed system powering the Stellar blockchain ledger and consensus. Develop scalable, resilient components; improve peer-to-peer networking and processing performance; investigate bottlenecks; and contribute to architecture, code reviews, RFCs, formal verification, simulations, and open-source collaboration. The role requires production C++ or Rust expertise, strong software design skills, and ownership of core subsystems.

Designs, develops, tests, deploys, and supports scalable full-stack enterprise applications for Fidelity’s retirement platforms. Builds RESTful APIs and transactional systems using C#, .NET, and Java; develops cloud-neutral, containerized services; participates in architecture and code reviews; modernizes legacy systems; supports production releases; and mentors junior developers within Agile Scrum teams.

Develop and sustain a high-performance geospatial collaboration and intelligence reporting tool. Responsibilities include implementing mission-driven enhancements, maintaining existing code, troubleshooting application interfaces, testing, integration, and resolving production issues. The developer will work with Java, C/C++, scripting languages, databases, search platforms, REST services, and Linux. Participation in a rotating pager schedule is required for emergency 24/7 support.

Leads hands-on full-stack development across architecture, implementation, testing, deployment, and support. Designs secure, scalable C#/.NET and Angular applications, cloud integrations, APIs, and data solutions on AWS. Guides developers, establishes engineering standards, manages CI/CD and automated testing, troubleshoots complex issues, and drives cloud optimization, security, and technical debt reduction. Collaborates with product, architecture, DevOps, analytics, and project teams while supporting migration of on-premises applications to AWS.

Lead a development team while remaining hands-on in full-stack engineering. Design, build, test, deploy, and support secure web applications using C#/.NET, Angular, databases, and AWS. Drive cloud migrations, architecture, CI/CD automation, application security, troubleshooting, performance and cost optimization. Mentor developers, establish engineering standards, lead technical delivery, and collaborate with product, data, DevOps, and architecture teams.

Develop and enhance enterprise SaaS solutions for an automotive intelligence platform using C#, .NET, SQL Server, Razor, Web API, HTML, and JavaScript. Own the full software development lifecycle, write scalable code, troubleshoot performance issues, contribute to architecture, collaborate in Agile teams, and mentor peers. The role requires extensive Microsoft development experience, Azure expertise, database optimization skills, and strong problem-solving ability.

Develops, implements, maintains, and supports MES software and infrastructure in a manufacturing environment. Responsibilities include C# and ASP.NET development, MES integrations, shop monitoring applications, reporting, hardware and software installation, network and system maintenance, troubleshooting, documentation, user training, and production stability. The role also designs and manages scalable Kubernetes clusters and automation scripts for provisioning and administration.

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.

Design, develop, integrate, test, deploy, and maintain high-performance DNS resolution software in a collaborative Agile environment. The role involves systems programming in C, C++, or Rust; networking and routing protocols; automated testing; CI/CD; infrastructure automation; vulnerability management; troubleshooting; and Linux-based distributed system operations. Engineers own features from design through delivery, contribute to technical leadership and best practices, and collaborate closely with team members.

Design, develop, and support reusable components, interactions, frameworks and SDKs for Spectacles AR glasses and SnapOS. Contribute to OS components, participate in code and design reviews, and collaborate with design, engineering, and product teams to launch performant, test-covered features.

Develops and maintains control-plane software for Layer 2 networking and switching systems. Responsibilities include requirements analysis, software design, C/C++ implementation, unit and integration testing, test automation, performance optimization, troubleshooting, root-cause analysis, and collaboration with architects and distributed teams. The role also contributes to technical specifications, customer issue resolution, standards, white papers, and patents.

Develop and optimize high-performance C++ numerical simulations for hydrology and water resources applications. Maintain and enhance Windows desktop software and cloud-based SaaS products, addressing computational efficiency, numerical stability, and large-scale data challenges. Collaborate with water resource engineers to translate scientific concepts into software, while contributing to architecture, code reviews, documentation, unit testing, debugging, and continuous improvement.

Develop and optimize a Windows desktop application featuring geospatial rendering, GIS visualization, and hydraulic model editing. Responsibilities include maintaining the rendering engine, implementing 2D/3D DirectX pipelines, developing computational geometry algorithms, integrating geospatial formats and coordinate systems, testing, documentation, code reviews, and mentoring junior engineers. The role collaborates with technical subject-matter experts to enhance the platform and support water resources engineering applications.

Lead end-to-end development of secure, scalable web applications and data solutions supporting clinical trial operations. Design frontend and backend components using C#/.NET, Angular, AWS, and relational or non-relational databases. Guide architecture, testing, deployment, CI/CD, security, cloud optimization, and regulatory compliance. Mentor developers, oversee technical delivery, troubleshoot complex issues, and lead migration and modernization of on-premises applications to AWS.