Senior .NET / Full Stack Developer — Long Island, NY

Gain America Inc.; New York, Northern (NY, KY); Hybrid; USD 120,000 - 150,000; Full time

Job summary

Gain America is seeking a Senior .NET / Full Stack Developer to own enterprise web applications on the Microsoft stack in the Long Island, NY market. You will build secure APIs and modern React front ends for high-traffic business systems, delivering end-to-end features.

Hybrid / on-site work with enterprise clients, collaborating with cross-functional teams. The role requires 5+ years shipping production software in C# / .NET, strong ASP.NET Core, Web API, EF, React/TypeScript, and hands-on

Qualifications

• 5+ years shipping production software in C# / .NET.
• Strong ASP.NET Core, Web API, and Entity Framework experience.

Responsibilities

• Build and maintain ASP.NET Core services and RESTful APIs for customer-facing applications.
• Develop responsive front ends in React/TypeScript against those APIs.
• Design and tune SQL Server schemas, queries, and stored procedures.
• Deploy and monitor workloads on Azure using App Services, Functions, and DevOps CI/CD.

Skills

C# / .NET

ASP.NET Core

React

TypeScript

Azure

Tools

Azure DevOps

SQL Server

Job description

Gain America is recruiting a Senior .NET / Full Stack Developer for contract and contract-to-hire engagements with our enterprise clients in the Long Island, NY market. Own enterprise web applications end to end on the Microsoft stack — building secure APIs and modern React front ends for high-traffic business systems.

Work model: Hybrid / on-site in the Long Island, NY area
Core stack: .NET, C#, ASP.NET Core, Azure, React/TypeScript, SQL Server

What you'll do

• Build and maintain ASP.NET Core services and RESTful APIs behind customer-facing applications
• Develop responsive front ends in React/TypeScript against those APIs
• Design and tune SQL Server schemas, queries, and stored procedures
• Deploy and monitor workloads on Azure using App Services, Functions, and DevOps CI/CD

What you bring

• 5+ years shipping production software in C# / .NET
• Strong ASP.NET Core, Web API, and Entity Framework experience
• Front-end proficiency with React and TypeScript
• Hands-on Azure and CI/CD experience

Gain America is a technology staffing partner placing skilled consultants with leading employers across financial services, insurance, healthcare, and the public sector. You'll work with a dedicated recruiter who advocates for you from first call through offer. Client names are shared once there is a mutual fit.