Lead II – Full Stack Developer (.NET Core + React)

Lead II – Full Stack Developer (.NET Core + React)

Lisle, IL (Onsite – 4 Days)
Contract
UST Global // Navistar

NOTE - We are looking for local candidates, as there will be F2F interview.

Job Summary

We are seeking a highly experienced Lead II – Full Stack Developer with strong expertise in .NET Core, ASP.NET, C#, and ReactJS to join a fast-paced Agile development team. The ideal candidate will have extensive experience building scalable enterprise applications, modernizing legacy ASP.NET Web Forms applications, developing RESTful APIs, and delivering high-quality software using modern development practices.

This role requires a hands-on developer who can contribute to application design, development, testing, code reviews, and technical leadership while collaborating with cross-functional teams.

Key Responsibilities

• Design, develop, and maintain enterprise web applications using ASP.NET/.NET Core, C#, and ReactJS.
• Modernize legacy ASP.NET Web Forms applications into .NET Core + React architecture.
• Develop and maintain RESTful Web APIs using .NET Core.
• Write clean, maintainable, and reusable code following SOLID principles and design patterns.
• Develop comprehensive unit tests and perform Web API testing.
• Optimize applications for performance, scalability, and security.
• Design and implement complex SQL queries, stored procedures, and database objects.
• Work with SOAP and REST services for system integrations.
• Participate in code reviews, refactoring initiatives, and technical design discussions.
• Collaborate with QA teams during testing and defect resolution.
• Follow Agile development methodologies and participate in sprint planning, daily stand-ups, and retrospectives.
• Support CI/CD implementation and application deployments.
• Work closely with architects, business stakeholders, and project managers to deliver high-quality solutions.
• Mentor junior developers and contribute to technical best practices.

Required Skills & Experience

• 6+ years of experience developing applications using ASP.NET / .NET Core with C#.
• 6+ years of hands-on experience with ReactJS.
• Strong experience developing RESTful Web APIs using .NET Core.
• Experience writing unit tests and performing API testing.
• Strong understanding of application security, scalability, and performance optimization.
• Experience migrating legacy ASP.NET Web Forms applications to modern React/.NET Core architecture.
• Strong knowledge of:
• HTML5
• CSS3
• JavaScript
• jQuery
• JSON
• XML
• Expert-level SQL skills including:
• Complex Queries
• Stored Procedures
• Performance Optimization
• Experience working with SOAP and REST services.
• Strong understanding of Object-Oriented Programming (OOP).
• Experience implementing SOLID principles and design patterns.
• Experience with GitFlow branching strategy.
• Experience using Git and TFS for source control.
• Familiarity with Azure.
• Experience working with CI/CD pipelines.
• Familiarity with ADO or Jira.
• Understanding of Kubernetes deployments.
• Experience working in Agile/Scrum environments.

Preferred Skills

• Experience with Telerik UI controls.
• Experience with application modernization projects.
• Exposure to DevOps practices.
• Leadership or mentoring experience.
• Strong analytical and problem-solving skills.

Responsibilities Beyond Development

• Participate in architecture and design discussions.
• Review code and enforce coding standards.
• Support effort estimation and sprint planning.
• Perform root cause analysis for production issues.
• Create and review technical documentation.
• Collaborate with customer stakeholders and technical teams.
• Ensure adherence to software engineering best practices and project timelines.
• Support release management and deployment activities.
• Mentor team members and promote knowledge sharing.

Required Technologies

• ASP.NET
• .NET Core
• C#
• ReactJS
• Web API
• SQL Server
• HTML5
• CSS3
• JavaScript
• jQuery
• JSON
• XML
• REST
• SOAP
• Git
• TFS
• Azure
• Kubernetes
• CI/CD
• ADO / Jira

Nice to Have

• Telerik
• DevOps exposure
• Legacy application modernization experience

Soft Skills

• Excellent communication skills.
• Strong analytical and troubleshooting abilities.
• Ability to work independently and collaboratively.
• Strong ownership and leadership mindset.
• Experience working in Agile teams.
• Ability to mentor junior developers and lead technical initiatives.