Top C# Jobs

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 data pipelines, datasets, APIs, storage systems, and research infrastructure supporting quantitative trading. Develop big data tooling for cluster and high-throughput computing, improve scalability and performance, manage data transmission between C++ and Python, and support releases, debugging, maintenance, and storage expansion. The role also involves leading technical projects and mentoring junior engineers.

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.

Lead modernization of a 30-year-old Store Management System by reverse engineering EZC file-based platforms, migrating data and applications to PostgreSQL, and developing enterprise C/C++ software. Responsibilities include architecture, systems integration, APIs, ETL, performance optimization, troubleshooting, documentation, and maintaining business continuity. The role also applies AI-assisted development tools for code analysis, documentation, testing, and modernization while mentoring teams and supporting legacy and modern environments.

Designs and implements cross-platform Android and iOS features using modern C++, including Chromium browser and OpenGL ES game-engine capabilities. Integrates on-device AI, LLMs, agents, and inference technologies while optimizing latency, memory, power, and performance. Collaborates across teams, integrates APIs and SDKs, writes tests, troubleshoots issues, and improves mobile application stability and responsiveness.

Leads development, architecture, validation, integration, and documentation of C++ medical imaging software and machine-learning-enabled clinical workflows. Collaborates with product, architecture, systems, testing, and AI/ML teams to deliver Azurion and IntraSight integration features. Translates requirements into BDD scenarios, supports Agile planning, contributes to risk management and FMEA, and ensures compliance with medical-device regulations and quality processes.

Develop and support AMDOTS data collection, retrieval, processing, transmission, reporting, ETL, SQL Server databases, and C++ software. Maintain Remote Monitoring Units, interfaces, networks, operating systems, software releases, documentation, disaster recovery plans, and user support. Provide data warehouse administration, technical troubleshooting, training, and site installation support in classified DoD environments, with periodic travel required.

Build and maintain C++ backend services, workflow automation, factory software, data pipelines, databases, and machine integrations supporting digital manufacturing. Develop tools for scheduling, production execution, process data collection, and operator workflows. Own infrastructure including build systems, CI/CD, deployment, AWS resources, and developer tooling. Collaborate with manufacturing and process engineering teams to automate and scale factory operations.

Develop and test full-stack software for a real-time hospital patient monitoring platform. Responsibilities include designing scalable and reliable components, writing technical specifications, implementing software solutions, reviewing code, mentoring engineers, optimizing performance, and applying engineering best practices in an Agile environment. The role uses C#, .NET, React, GraphQL, databases, and cloud-native technologies while collaborating with cross-functional teams.

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.

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.

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.

Develop and maintain large Python systems and C/C++ software supporting national security missions. Use Bash and other scripting languages, analyze RF signals, and work with embedded hardware, STM32 microcontrollers, Raspberry Pi devices, digital logic, and hardware debugging tools. The role requires a Top Secret/SCI clearance with favorable polygraph, 15 years of relevant software engineering experience, and a bachelor's degree or equivalent experience.

Leads customer-facing development, deployment, administration, and evolution of mission-critical satellite communication systems. Builds and manages complex environments using C++ or Python, Kubernetes, GPU technologies, Linux, Ansible, and DevOps practices. Responsibilities include Kubernetes cluster lifecycle management, automation, networking, security hardening, monitoring, storage, software testing, requirements gathering, stakeholder communication, and presenting technical concepts to nontechnical audiences.

Build and validate reinforcement-learning tasks for AI agents exploring unfamiliar C repositories. Responsibilities include investigating runtime behavior, rewriting engineering questions, refining rubrics and foils, running validation workflows, documenting solutions, and addressing expert review. Work focuses on production systems such as PostgreSQL, Redis, OpenSSH, OpenSSL, and other foundational C codebases.

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 high-performance C++ software and Python tooling for clinical trial analytics. Translate statistical algorithms and research prototypes into scalable production software, optimize performance and memory usage, build automated tests, and support validation and deployment of computational models. Collaborate with researchers, statisticians, product managers, and engineers on data-intensive systems, architecture, automation, machine learning, and research innovation.

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.

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.

Develop and maintain a high-performance C++ quantitative library for options analytics. Responsibilities include API and library design, performance profiling and optimization, implementing numerical pricing models, code reviews, developer support, build and CI improvements, testing, documentation, and AI-assisted development. The role works closely with quants and the CTO in a small hybrid team.

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.