Top Senior .NET Developer Jobs in Denver & Boulder, CO

Lead development and support of enterprise insurance applications on the Microsoft .NET stack. Design, build, and maintain secure, scalable systems and integrations, troubleshoot production issues, modernize architecture and cloud adoption, and improve CI/CD and automated testing while collaborating with product, project, and business stakeholders.

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

Design, build, and maintain production-grade .NET web applications and APIs on Azure. Own full-stack delivery from data models and SQL to front-end components, CI/CD, testing, and architecture. Collaborate with product and delivery teams, participate in code reviews, and ensure secure, observable, well-tested services.

Seeking a Senior Full Stack .NET Developer to work on a social good project, with strong skills in C#, AngularJS, design, and UX. Requires 5+ years of experience.

The Staff Engineer will leverage 5+ years of experience in C#, JavaScript, and frameworks to lead and innovate solutions in a collaborative environment.

Senior .NET Developer to build a Compliance System (ORCA). Develop distributed RESTful web/cloud services and Web APIs using ASP.NET/C#, backend databases (MongoDB, SQL Server 2012), and frontend tech (AngularJS, HTML/JavaScript, Bootstrap). Work with AWS and Pivotal products; deliver enterprise-grade solutions.

Senior .NET full-stack developer responsible for custom application development, API integrations, database optimization, deployments, troubleshooting, performance, security, and production support using .NET/C#, ASP.NET Core, SQL, modern frontend frameworks, cloud, and CI/CD.

Design and develop middle-tier applications and services using Visual Studio 2013, .NET 4.5 and C#. Implement and maintain web/WCF/windows services, perform unit and integration testing, tune .NET performance, create installation/maintenance documentation, collaborate with development, QA, product and project teams, and work in an Agile environment to improve processes and deliver multi-tier applications.

Provide technical leadership to design, modernize, and sustain a portfolio of .NET web applications and Azure infrastructure. Develop and migrate WebForms to ASP.NET Core and SSRS to Power BI, maintain SQL Server databases, enforce secure coding and ATO compliance, ensure accessibility (Section 508/WCAG), and mentor junior developers while coordinating with VA stakeholders.

Design, build, and maintain scalable web applications for payroll and accounting. Collaborate with engineers and product partners, write tested code, participate in code reviews, contribute to architecture, improve CI/CD and monitoring, support production (including on-call), and communicate progress while continuously learning.

Full‑stack senior .NET developer responsible for 80% hands‑on development, code reviews, mentoring, and 20% testing, deployment, and design. Deliver clean, well‑documented, high‑performance applications using C#, ASP.NET/MVC, SQL Server and UI libraries, integrate with web services, and guide teammates to robust solutions.

Design, develop, test, and deploy .NET solutions (APIs and web apps). Build and consume RESTful services, work with SQL and NoSQL databases, use cloud (Azure/AWS) and Docker, apply unit/integration/performance testing, participate in code reviews, define features via spikes, and architect scalable, high-performance systems. Support occasional after-hours and on-call rotation.

Develop and maintain web applications using .NET technologies. Collaborate on design patterns, web services, and front-end development with a focus on security and performance.

Lead architecture and hands-on development for a core SaaS product suite (50% coding). Own technical roadmap, drive DevSecOps/IaC/TDD adoption, mentor teams, resolve performance and reliability issues, and translate product needs into scalable designs.

Develop and maintain web-based applications using .NET/C#, JavaScript, HTML/CSS, SQL and Oracle/SQL Server. Perform root cause analysis, collaborate with teams for requirements, follow Agile SDLC, present change demonstrations, and use Azure DevOps/Jira for lifecycle management. Implement and maintain Blazor components.

Senior .NET Software Engineer responsible for end-to-end software development using Microsoft technologies. Requires extensive experience in SDLC, design principles, technical documentation, web application development with .NET, Agile/SCRUM, Entity Framework, database design, and version control. Familiarity with project tools JIRA, TEMPO, Bitbucket, and Confluence preferred.

Senior .NET Web App Developer responsible for designing and building .NET web applications, implementing Oracle PL/SQL solutions, using Entity Framework and Blazor, applying design principles, producing technical documentation, performing performance tuning, and collaborating in Scrum/Agile teams with Bitbucket, JIRA, Tempo, and Confluence.

The Senior .NET Developer will work on developing and maintaining applications, mentor junior developers, and ensure compliance with regulations. The role requires expertise in full-stack development, particularly with SQL Server databases and Azure.

The Senior .Net Developer will enhance SDG's C#/.NET Core codebase, design high-load services, and optimize MS SQL queries, benefiting from a remote work environment and attractive benefits.

As a Senior Software Engineer at PerfectServe, you'll design, build, and maintain high-quality code for healthcare communication systems, mentoring junior engineers and collaborating across teams to improve patient care and clinical workflows.

Lead backend development on the scheduling platform modernization, contribute across products, write APIs, and drive AI-accelerated software development workflows.

Lead backend development on the scheduling platform modernization. Contribute across Python and .NET ecosystems, write APIs, review code, and support AI-accelerated development workflows while collaborating in a remote team environment.

The Senior .NET Software Engineer will drive development of .NET software products, focusing on back-end engineering, code reviews, and collaborating with cross-functional teams.

The Senior Full Stack Engineer will modernize legacy systems to microservices, maintain .NET applications, optimize SQL databases, and develop frontend interfaces.

As a Senior Software Developer, you'll design, build, deploy, and support web applications using the .NET stack and Azure, while collaborating with a team.