Top Senior C# Jobs

You will develop and maintain components of the LLVM based toolchain, collaborating with the community while ensuring platform-specific optimizations and tests.

Design, develop, and deploy web and cloud applications using .NET, C#, Azure, Angular, React, and related technologies. Collaborate with clients to gather requirements, define goals, and recommend solutions. Participate in Agile/Scrum planning, code reviews, mentoring, testing, and DevOps practices. Explore AI-assisted development tools and help establish effective AI workflows. The role involves continuous learning, client engagement, and delivery of enterprise software and AI automation solutions.

Design, develop, and enhance a scalable loan origination system. Build accessible user-facing features, APIs, microservices, and resilient distributed systems using .NET, C#, and Azure. Collaborate with architecture, product, design, and engineering teams; improve performance, availability, monitoring, security, and deployment automation. Work with databases, containers, messaging, CI/CD, and cloud-native architectures.

Develop and productize mission-focused software for deployment across Department of Defense environments. Responsibilities include removing customer-specific dependencies, abstracting configurations, building authorization and key-management interfaces, and supporting Java, C++, cryptography, encryption libraries, and OpenBao services. The role also involves migrating code across security environments, applying software best practices, testing, defect resolution, project planning, and collaboration with technical teams and clients.

Design, build, and maintain web pages and web applications end-to-end. Coordinate with other development teams (D365 CRM, D365 Finance & Ops, Azure, mobile, MFA). Enhance and support multiple systems including Client Portal, Payroll Processing, SharePoint, Data Factory, and Integration Services. Gather and document requirements, participate in usability testing, optimize code for performance and reliability, and troubleshoot issues while collaborating with stakeholders.

Develop and maintain C#/.NET applications. Requires 5+ years C# experience plus knowledge of C/C++, VB, ActiveX, COM objects, and IPC. MATLAB experience is a plus. Strong communication, organization, teamwork, and a relevant bachelor's degree required.

Design, extend, and operate enterprise-scale Ceph clusters and core subsystems in C++; optimize performance, implement multi-site DR, integrate with Kubernetes and CI/CD, build automation, observability, encryption/KMS, and maintain production-grade SOPs and documentation.

The Senior Software Engineer will design, develop, and maintain software applications using Python, C#, C++, and Linux, while collaborating with cross-functional teams to optimize performance and user experience.

Develop geocoding and location-based APIs, optimize algorithms and data structures, and maintain scalable C++ code for Esri's software products.

Design, build, and maintain high-throughput, low-latency C++ systems for symbol resolution. Develop scalable APIs, participate in design/code reviews, monitor and troubleshoot production, champion best practices, and mentor teammates.

Design, build, and maintain scalable, reliable distributed systems and backend services for a Linux-based cyber-recovery platform. Drive architecture, write and test C/Python code, develop RESTful APIs, improve performance and resilience, resolve production issues, participate in code reviews, mentor junior engineers, and collaborate with Product, QA, DevOps, and Security teams.

Develop and maintain DIAMONDS and other enterprise applications using C# and Oracle/PL/SQL. Participate in full software lifecycle (design, coding, testing, configuration management, release, IV&V support), build WPF/Prism features, apply secure coding and static analysis tools, support sustainment and customer-facing requirements gathering, and follow CMMI/Agile processes and Git/Azure DevOps workflows.

Develop and optimize high-throughput C++ algorithms for remote sensor data exploitation (image analysis, detection, tracking). Prototype, integrate, and test software within government frameworks as part of an Agile team. Work full-time in-person in Boulder, CO and obtain/maintain DoD security clearance.

Develop, optimize, and integrate high-throughput C++ algorithms and multi-object tracking software for counter-UAS and remote sensing systems. Work in an Agile small-team environment to prototype, test, and deliver low-latency processing solutions within government frameworks.

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 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.

Design, implement, and maintain low-latency C++ applications for trading strategy execution, optimizing performance, and collaborating with traders and engineers.

Develop, enhance, and maintain backend web applications and services using C#/.NET. Implement features with ASP.NET, Entity Framework, and SQL Server; write unit and integration tests; perform troubleshooting, code reviews, vulnerability remediation, and O&M tasks while collaborating with senior engineers and cross-functional teams.

C# developer for fixed income/commodities front-office technology. Full SDLC with support responsibilities; build and maintain trading systems, databases, and UIs using .NET, DevExpress, messaging middleware, SQL Server/Sybase. Requires strong debugging/triage and communication skills. Unit testing and meta-programming, OpenLink/ETRM, and trading product knowledge are desired.

Lead C#/.NET Developer to design and implement healthcare-focused software and integrations. Responsibilities include C#/.NET development, SOAP/REST services, PowerShell automation, HL7/CCD/CCR healthcare interchange, ETL/MDM using Informatica, Oracle/PLSQL work, merging very large datasets, and specifying/conducting system and user acceptance testing.

Develop, design, test, and maintain C# applications on a collaborative Scrum team. Work on new system development and enhancements, participate in implementations, and produce/update documentation. Full-stack skills and teamwork required; JavaScript experience preferred.

Design, architect, and build payment and transaction processing applications using C#/.NET. Lead cross-functional meetings, produce high-quality optimized code, implement web services, and collaborate with teams to deliver scalable, maintainable solutions.

As a Senior Software Engineer, lead the development of real-time machine control systems for 3D metal printing platforms, influencing system performance and reliability. Mentor engineers, define software standards, and drive initiatives for system robustness and scalability.

Design and implement real-time machine control software for 3D metal printing systems while collaborating with multidisciplinary engineering teams to enhance system reliability and performance.