Senior / Lead .NET Developer

American IT Systems•Lisle, IL

11d

About The Position

This role involves designing, developing, testing, deploying, and maintaining enterprise applications using C#, ASP.NET, ASP.NET Core, MVC, Web API, and related Microsoft technologies. The position focuses on modernizing legacy .NET applications and services to enhance performance, reliability, maintainability, and user experience. It also includes building and consuming RESTful APIs, developing responsive user interfaces, and optimizing database operations. The role requires participation in all phases of the software development lifecycle, including requirements gathering, technical design, estimation, documentation, testing, and implementation, while supporting Agile methodologies. Production support, troubleshooting, and root cause analysis are also key aspects, along with collaboration across various teams and contribution to CI/CD pipelines.

Requirements

10+ years of professional software development experience, preferably with significant hands-on experience in the Microsoft technology stack.
Strong experience with C#, .NET Framework, ASP.NET, ASP.NET Core, MVC, Web API, ADO.NET, Entity Framework, WCF, and related technologies.
Experience developing and supporting N-tier, client/server, web-based, and service-oriented applications.
Strong database development skills with SQL Server, including query optimization, stored procedures, triggers, and performance tuning.
Experience with front-end development using HTML5, CSS, Bootstrap, JavaScript, jQuery, Angular, React, JSON, and AJAX.
Working knowledge of object-oriented programming principles, SOLID principles, design patterns, and clean coding practices.
Experience with source control, DevOps, and delivery tools such as Azure DevOps, GitHub, TFS, Visual Studio, VS Code, Postman, and SoapUI.
Ability to create technical design documents, use cases, test cases, deployment documentation, and user-facing documentation.
Strong analytical, troubleshooting, communication, and stakeholder-management skills.

Nice To Haves

Experience leading small development teams or coordinating work between onshore and offshore teams.
Experience with application modernization, legacy system remediation, technical debt reduction, and platform upgrades.
Experience integrating third-party services, AI-enabled services, transcript/document processing, or business workflow automation.
Experience in manufacturing, automotive, legal technology, industrial, or enterprise business systems environments.
Familiarity with Oracle, DB2, LiteDB, PostgreSQL, SharePoint, IIS, Windows Server, and cloud-oriented delivery practices.
Bachelor's degree in Computer Science, Information Technology, Engineering, or a related field preferred; equivalent professional experience may be considered.
Advanced degree or formal computer applications education is a plus.
Relevant Microsoft, .NET, cloud, DevOps, database, or application development certifications are preferred.

Responsibilities

Design, develop, test, deploy, and maintain enterprise applications using C#, ASP.NET, ASP.NET Core, MVC, Web API, and related Microsoft technologies.
Modernize legacy .NET applications and services to improve performance, reliability, maintainability, and user experience.
Build and consume RESTful APIs and web services to support integrations with internal and external systems.
Develop responsive user interfaces using HTML5, CSS, Bootstrap, JavaScript, jQuery, Angular, and React where applicable.
Create and optimize SQL queries, stored procedures, triggers, indexes, and database objects across SQL Server and other relational databases.
Participate in requirements gathering, analysis, technical design, solution estimation, documentation, testing, and implementation activities.
Support Agile delivery practices, including sprint planning, backlog refinement, code reviews, unit testing, and release coordination.
Provide production support, troubleshoot application issues, analyze root causes, and implement corrective actions.
Collaborate with business users, product owners, QA teams, infrastructure teams, and offshore/onshore development teams.
Contribute to CI/CD pipelines, source control practices, build automation, and deployment processes using tools such as Azure DevOps, GitHub, and TFS.