Top .NET Developer Jobs in St. Louis, MO

Develop and support enterprise B2B and B2C eCommerce solutions using .NET/C# and Optimizely Configured Commerce. Build commerce capabilities, integrations, APIs, and event-driven services; troubleshoot application and database issues; optimize performance, scalability, accessibility, and SEO; participate in code reviews; and collaborate with product, architecture, frontend, integration, and business teams.

Leads architecture and development of complex backend services for a commercial health plan platform. Designs .NET Core and Azure systems, develops claims, eligibility, and benefits functionality, manages healthcare data integrations, and owns cloud infrastructure and CI/CD architecture. Provides technical leadership through code reviews, testing standards, mentoring, and architecture decisions while ensuring performance, reliability, security, and regulatory compliance.

Design, develop, test, secure, and maintain enterprise applications and APIs using C# and modern .NET. Build database solutions, RESTful integrations, automated tests, and CI/CD pipelines while supporting Agile and DevSecOps delivery. Modernize legacy applications, troubleshoot production issues, conduct code and design reviews, and remediate security findings. The role requires an active DoD Secret clearance and U.S. citizenship and is remote within the United States during Pacific Standard Time hours.

Develop and optimize Microsoft .NET applications, legacy systems, and microservices with a focus on performance, scalability, reliability, and observability. Responsibilities include code reviews, performance testing, CI/CD integration, architecture and sprint delivery, legacy code and SQL tuning, cloud application deployment on Azure, automated testing, and resolving customer issues. The developer collaborates with architects, QA, technical support, and cross-functional teams using SAFe Agile practices.

Design, develop, deploy, and support enterprise integration solutions using C#, .NET, Azure, APIs, microservices, middleware, and Azure Service Bus. Integrate SAP, Dynamics 365 CRM, IVR systems, databases, payment gateways, and traffic management platforms. Build secure, scalable, high-volume data exchanges, troubleshoot production issues, document technical solutions, and support implementation and post-go-live activities, including scheduled onsite work in Middletown, Pennsylvania.

Build and maintain C#/.NET backend services, APIs, web applications, ERP and billing features, and financial integrations. Modernize legacy .NET Framework applications onto Azure, optimize SQL Server and Azure SQL data access, create automated tests, support CI/CD, instrument production systems, and implement secure authentication and configuration. Troubleshoot application, database, and hosting issues while collaborating with DevOps, architects, product leaders, and stakeholders.

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.

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.

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.

Leads the design, development, and implementation of full-stack applications using C#, .NET, Angular, Azure, and SQL Server. Collaborates with cross-functional teams, ensures application security, performance, and scalability, applies Git-based version control practices, mentors developers, and stays current with emerging technologies.

Build and maintain scalable, cloud-native APIs and high-value core system components using .NET and related technologies. Lead software architecture and testing discussions, enhance core offerings, collaborate cross-functionally, and ensure quality through code reviews, unit testing, functional testing, telemetry, and performance tuning. Mentor teammates and contribute to continuous technical and process improvement.

Lead development of secure, scalable digital banking software across front-end and backend systems. Design Angular or React applications, build APIs, optimize SQL performance, integrate third-party platforms, improve code quality, implement testing strategies, and mentor engineers. Collaborate with cross-functional teams in an Agile environment while supporting cloud-native practices, regulatory compliance, and continuous product improvement.

Owns the design, development, testing, deployment, and maintenance of production software. Builds C#/.NET backend services, Angular web applications, and .NET MAUI mobile apps; optimizes SQL Server databases; resolves production issues; improves reliability, security, performance, and observability; writes tests and documentation; participates in code reviews; and translates ambiguous business needs into maintainable technical solutions.

Build scalable backend-heavy services and applications using C# and .NET, while contributing to Angular and TypeScript UI development. Design and develop REST APIs and microservices, work with relational databases, implement automated testing and CI/CD, and ensure system security, scalability, and performance. Preferred work includes event-driven architectures, messaging systems, NoSQL databases, caching, search technologies, and mentoring engineers or leading technical initiatives.

Leads end-to-end modernization from a monolith to microservices, including legacy analysis, architecture, estimation, data migration, deployment, and production support. Guides .NET services, databases, messaging, containerization, and frontend integrations. Acts as the technical escalation point for complex issues while improving Jira tracking, estimation accuracy, QA collaboration, release predictability, and engineering processes. Manages and develops the team through one-on-ones, performance reviews, feedback, and career-focused objectives.

The C# / .NET Developer will design and maintain middleware applications, build Shopify integrations, and support a mobile app backend in a remote work 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 .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.

Develop and implement Java/J2EE server-side applications, translate functional requirements to system design, build REST/SOAP web services, work with PL/SQL and telecom domain systems, and use build/version tools (Eclipse, ANT, SVN) to deliver solutions.

Lead design and delivery of scalable, reliable software using C#/.NET, SQL Server, React, and Azure. Own complex initiatives from design through operations, mentor engineers, improve CI/CD, observability, and apply DDD/TDD/VSA practices. Use modern APIs, microservices or modular monoliths, and AI-assisted tooling to improve delivery.

Develop web solutions using .NET and React for various clients, collaborating with designers and strategists to deliver high-quality applications.

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 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.