Senior .NET Front-End Developer

Position Overview The Illinois Department of Healthcare and Family Services (HFS) is seeking a highly skilled Senior .NET Front-End Developer to support the design, development, modernization, and maintenance of enterprise-class web applications that enable the delivery of critical healthcare and public service programs. This position will play a key role in architecting and developing modern, scalable, secure, and highly accessible Single Page Applications (SPAs) that deliver exceptional user experiences while integrating seamlessly with enterprise Microsoft technologies and backend services. The ideal candidate will possess strong expertise in frontend engineering, modern web application architecture, and full-stack development using the Microsoft technology stack. The successful candidate will have demonstrated experience designing reusable component-based solutions, implementing scalable frontend architectures, optimizing application performance, and establishing engineering standards that promote maintainability, quality, accessibility, and security. This role requires close collaboration with UX designers, backend developers, database engineers, architects, product owners, and business stakeholders to deliver innovative, high-performing digital solutions that align with HFS technology standards and strategic modernization initiatives. In addition to hands-on development, the selected candidate will provide technical leadership through architecture reviews, code quality initiatives, mentoring, development standards, CI/CD implementation, and software engineering best practices while supporting Agile delivery teams throughout the Software Development Lifecycle (SDLC).

Key Responsibilities Design, develop, enhance, and maintain enterprise-scale Single Page Applications (SPAs) that support mission-critical HFS business operations. Lead frontend architecture efforts by designing scalable, reusable, and maintainable component-based solutions using modern TypeScript and JavaScript frameworks. Develop responsive, user-friendly, and highly accessible web applications that comply with WCAG 2.x, Section 508, and ADA accessibility standards. Design and implement frontend state management strategies that improve scalability, maintainability, and application performance. Collaborate with backend development teams to build integrated full-stack solutions utilizing ASP.NET Core, .NET Core, Entity Framework Core, LINQ, and RESTful APIs. Develop and consume secure RESTful web services while integrating enterprise applications with Microsoft SQL Server and Teradata databases. Optimize frontend application performance through code optimization, browser compatibility improvements, responsive design, lazy loading, and Search Engine Optimization (SEO) best practices where applicable. Design and maintain reusable UI components, enterprise design standards, and shared frontend libraries that improve development consistency across multiple applications. Establish frontend engineering standards, coding guidelines, testing methodologies, source control strategies, and CI/CD quality gates. Lead peer code reviews, mentor software developers, and promote software engineering best practices that improve code quality, maintainability, and application reliability. Partner with UX designers and business analysts to translate functional and technical requirements into scalable enterprise solutions. Participate in solution architecture reviews, technical design sessions, sprint planning, backlog refinement, estimation, and Agile ceremonies. Develop automated testing strategies that improve application quality and deployment reliability. Utilize Team Foundation Server (TFS) and Git for source control, version management, release coordination, and deployment activities. Troubleshoot application issues, perform root cause analysis, support production deployments, and implement application enhancements. Produce and maintain technical documentation, architecture diagrams, coding standards, implementation guides, and knowledge transfer materials. Required Qualifications & Technical Skills Bachelor's degree in Computer Science, Information Technology, Engineering, or a related field, or equivalent professional experience. Minimum three (3) years of experience in frontend engineering with demonstrated ownership of architecture for enterprise-scale Single Page Applications (SPAs). Proven experience designing, developing, and supporting enterprise full-stack applications utilizing Microsoft Visual Studio, ASP.NET Core, .NET Core, C#, Entity Framework Core, LINQ, and RESTful APIs. Strong expertise in TypeScript, JavaScript (ES6+), HTML5, CSS3, Responsive Web Design, Component-Based Architecture, Frontend State Management, and modern web application development practices. Experience designing reusable UI components, enterprise design standards, and scalable frontend architectures that promote maintainability and code reusability. Minimum three (3) years of experience with Microsoft SQL Server and two (2) years of experience with Teradata, including SQL development, query optimization, and integration with enterprise data-driven applications. Demonstrated expertise implementing WCAG 2.x, Section 508, and ADA accessibility standards, along with frontend performance optimization, browser compatibility, application scalability, and SEO best practices where applicable. Experience establishing frontend engineering standards, coding conventions, automated testing strategies, Continuous Integration/Continuous Deployment (CI/CD) pipelines, and Secure Software Development Lifecycle (Secure SDLC) practices. Hands-on experience utilizing Team Foundation Server (TFS), Git, source code management, version control, build automation, release management, and deployment processes. Proven ability to conduct technical design reviews, perform peer code reviews, mentor development teams, and provide technical leadership while promoting software engineering best practices. Strong understanding of Agile/Scrum methodologies and experience collaborating effectively with UX designers, solution architects, backend developers, database engineers, QA teams, business analysts, and executive stakeholders throughout the Software Development Lifecycle (SDLC). Excellent analytical, troubleshooting, problem-solving, organizational, verbal, and written communication skills, with the ability to manage multiple priorities and deliver high-quality solutions within fast-paced enterprise environments. Preferred Qualifications Experience developing and maintaining enterprise design systems and reusable UI component libraries. Strong experience in leading a small team developing, enhancing, and maintaining enterprise applications using Java and the Apache Struts Framework. Experience implementing micro-front end or modular application architectures. Experience supporting Healthcare, Medicaid, Human Services, or other State Government digital modernization initiatives. Experience developing secure, scalable, accessibility-compliant, and citizen-facing enterprise applications within highly regulated environments.