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Senior Full-Stack .NET Modernization Developer

Xcelo Group IncAtlanta, GA🇺🇸United StatesPosted Sep 22, 2026

Quick Overview

Seniority
Mid Senior
Work mode
Hybrid
Location
Atlanta, GA, United States
Posted
Yesterday
SQLSQL ServerT-SQLScrumAgileAzureC#.NETASP.NETGitKanbanPower BIRESTReact

Job Description

Hi,
We are having immediate requirement on below mentioned JD;

Job Title: Senior Full-Stack .NET Modernization Developer

Work Location: Atlanta, GA
Candidate Requirement: Local Atlanta, GA candidates only
Work Mode: Hybrid
Work Auth: Any Visa accepted (No H1 and No Fake Profile)

Experience Required: 10+ years

Role Overview

We are seeking a highly experienced Senior .NET Developer / Application Modernization Engineer to support the modernization of a mission-critical statewide licensing and eligibility platform.

The ideal candidate will have strong hands-on experience modernizing legacy ASP.NET applications to modern .NET 6/7/8/10, building secure and scalable REST APIs, developing React components, working with Azure cloud services, and managing complex SQL Server environments.

This is not a pure maintenance role. The selected candidate will be expected to take ownership of solutions from design and development through testing, deployment, documentation, and production support.

Required Education

  • Bachelor's degree in Computer Science, Information Technology, or a related field

  • Equivalent professional experience may be considered


Required Experience

  • 10+ years of overall professional software development experience

  • Strong hands-on experience with:

    • C#

    • ASP.NET MVC

    • ASP.NET Web API / REST APIs

  • Proven experience modernizing production applications from legacy ASP.NET to .NET 6, 7, 8, or 10

  • Must have completed real-world application modernization initiatives, not only proof-of-concept work

  • 5+ years of Agile delivery experience using Scrum or Kanban

  • Experience with Azure DevOps or GitHub

  • Strong production troubleshooting and root-cause analysis experience


Core Technical Requirements

<>.NET Application Modernization
  • Lead modernization of legacy enterprise applications to modern .NET 8+ / .NET 10

  • Design scalable, secure, maintainable application architectures

  • Reduce technical debt and improve platform maintainability

  • Participate in application architecture and technical design decisions

  • Strong understanding of modern .NET application patterns and best practices


<>REST API Development
  • Design, build, and maintain RESTful APIs

  • Experience supporting APIs consumed by external systems

  • Strong understanding of API contracts, integration patterns, error handling, versioning, and documentation

  • Experience building API-first enterprise applications


<>React / Frontend Development
  • Minimum 3 years of React experience

  • Must have experience building and enhancing React components within an existing enterprise application

  • Strong understanding of:

    • Component-based architecture

    • Client-side rendering (CSR)

    • Server-side rendering (SSR)

    • Modern frontend development patterns


<>Microsoft Azure

Strong hands-on experience with:

  • Azure App Services

  • Azure Function Apps

  • Application configuration management

  • Cloud deployments

  • Azure-based application integration

  • Deployment and release pipelines

  • Azure DevOps CI/CD


<>SQL Server

Strong production experience with:

  • SQL Server

  • T-SQL

  • Stored procedures

  • Query and performance tuning

  • Schema changes and migrations

  • Data cleanup

  • Data migration

  • Database troubleshooting

  • Data architecture


<>CI/CD & DevOps
  • Develop and maintain CI/CD pipelines using Azure DevOps

  • Automate builds, testing, releases, and deployments

  • Support configuration and environment management

  • Experience with Git-based development workflows

  • Strong code review, release management, and deployment practices


Reporting Experience

Minimum 3 years of experience with one or both of the following:

  • Power BI

  • SSRS


Integration Experience

  • Experience integrating third-party services and internal enterprise APIs

  • Strong API and middleware integration background

  • Experience with middleware platforms such as:

    • Boomi

    • MuleSoft


AI / Azure AI Exposure

Preferred experience with:

  • Azure Agentic AI services

  • Azure AI integrations

  • Microsoft Copilot-related tooling

  • Chatbot integrations

  • AI-driven features integrated into production applications


Accessibility & Compliance

Preferred experience with:

  • ADA / WCAG 2.1 AA accessibility standards

  • Government, healthcare, or public-sector applications

  • Compliance and auditability requirements

  • PII data

  • Data security and privacy controls


Domain Experience

Minimum 3 years of experience in one or more of the following environments is preferred:

  • Government

  • State or public-sector systems

  • Healthcare

  • Highly regulated enterprise applications


Key Responsibilities

  • Modernize legacy ASP.NET applications to modern .NET and Azure-based architectures

  • Design scalable and secure enterprise application solutions

  • Develop cloud-native applications using Azure services

  • Build and enhance React user interfaces

  • Develop and maintain enterprise REST APIs

  • Own SQL Server performance, migration, and modernization activities

  • Create and maintain CI/CD pipelines through Azure DevOps

  • Integrate internal and external services

  • Develop Power BI and/or SSRS reports

  • Support Azure AI, Copilot, chatbot, and Agentic AI integration initiatives

  • Conduct code reviews and architecture reviews

  • Troubleshoot production issues independently

  • Perform root-cause analysis and implement long-term fixes

  • Maintain technical documentation, deployment runbooks, and support guides

  • Participate in Agile ceremonies and sprint delivery

  • Take ownership of assigned solutions from concept through production


Must-Have Skills

10+ Years Experience, Local Atlanta GA, C#, ASP.NET MVC, ASP.NET Web API, .NET 6/7/8/10, Legacy Application Modernization, React, REST APIs, Microsoft Azure, Azure App Services, Azure Functions, Azure DevOps, CI/CD, SQL Server, T-SQL, Stored Procedures, Agile, Git

Preferred Skills

Power BI, SSRS, Azure Agentic AI, Copilot, Chatbots, Boomi, MuleSoft, ADA, WCAG 2.1 AA, PII, Government, Healthcare, Public Sector

Important Candidate Screening Criteria

  • Local Atlanta, GA candidates only

  • 10+ years of overall experience required

  • Strong hands-on legacy ASP.NET to modern .NET migration experience

  • Strong Azure + SQL Server + REST API experience

  • Hands-on React development within existing enterprise applications

  • Must be capable of independently owning technical solutions and resolving production issues


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