Senior .NET & React Developer — Hybrid Onsite (Lisle, 4 days)

TalentFish; Lisle (IL); Hybrid; USD 110,000 - 160,000; Full time

Job summary

TalentFish in Lisle, IL is seeking a Senior .NET/React Developer to join a major enterprise modernization initiative. You will transform legacy ASP.NET/Web Forms into .NET Core + React, build APIs, and strengthen architecture to support critical production systems.

This role requires working onsite in Lisle 4 days per week with a strong full-stack background and a collaborative, agile mindset. The ideal candidate has 5+ years in C# / .NET and 3+ years in ReactJS, plus practical CI/CD experience.

Qualifications

• 5+ years of hands-on C# / ASP.NET / .NET Core development.
• 3+ years of ReactJS experience.
• Experience modernizing legacy ASP.NET/Web Forms to .NET Core + React.
• Advanced SQL with complex queries and stored procedures.
• Unit testing and API testing.
• Strong understanding of OOP, SOLID, design patterns and refactoring.
• Git/GitFlow and Agile development experience.
• Experience with CI/CD and modern DevOps practices.
• Experience with Azure, Kubernetes, containerization, IaC, Telerik is a plus.

Responsibilities

• Modernize legacy ASP.NET/Web Forms apps into .NET Core + React.
• Build and expose APIs and strengthen application architecture.
• Support mission-critical systems and ensure stability.
• Collaborate with an established engineering team in a hybrid on-site setting.
• Contribute to CI/CD pipelines and DevOps practices.

Skills

C# / ASP.NET / .NET Core

ReactJS

SQL

Unit testing

API testing

OOP / SOLID / design patterns

Git / GitFlow

Agile development

CI/CD / DevOps

Azure

Kubernetes

Containerization

Infrastructure as code

Telerik

Tools

Kubernetes

Telerik

Job description

TalentFish in Lisle, IL is seeking a Senior .NET/React Developer to join a major enterprise modernization initiative. You will transform legacy ASP.NET/Web Forms into .NET Core + React, build APIs, and strengthen architecture to support critical production systems.

This role requires working onsite in Lisle 4 days per week with a strong full-stack background and a collaborative, agile mindset. The ideal candidate has 5+ years in C# / .NET and 3+ years in ReactJS, plus practical CI/CD experience.