Senior Full-Stack .NET Developer (Security & Modernization)

EPAM Systems; United States; Remote; USD 120,000 - 180,000; Full time

Job summary

EPAM Systems is seeking a Senior Full-Stack .NET Developer skilled in both legacy .NET Framework and modern .NET (6/8+). The role focuses on security remediation, legacy support, and modernization across multi-tier applications.

You will remediate OWASP Top 10 findings, maintain Web Forms, MVC, WCF, and ASMX apps, and develop ASP.NET Core Web APIs. Strong SQL Server and frontend skills are required.

Qualifications

• 3+ years of full-stack .NET development experience.
• Strong C#, .NET Framework, and SQL Server knowledge.
• Proficiency in ASP.NET Web Forms and MVC.
• Experience with .NET 6/8+, ASP.NET Core, and REST APIs.
• Understanding of dependency injection.
• Security experience with OWASP Top 10.
• Experience with React, Angular, or Vue.js.
• Strong troubleshooting and legacy codebase skills.
• English proficiency at B2 or higher.

Responsibilities

• Investigate and remediate application security vulnerabilities, including OWASP Top 10, SAST/DAST findings, SQL injection, XSS, and dependency risks.
• Maintain and modernize legacy ASP.NET Web Forms, MVC, WCF, and ASMX applications.
• Develop and enhance ASP.NET Core Web APIs and modern .NET services.
• Work with SQL Server, ADO.NET, EF Core/Dapper, ensuring secure data access.
• Support frontend development using HTML, CSS, JavaScript/TypeScript, jQuery, and modern SPA frameworks.
• Collaborate with DevOps to support secure CI/CD and production deployments.

Skills

C#/.NET

SQL Server

ASP.NET Web Forms

ASP.NET MVC

ASP.NET Core

REST APIs

Security Practices

Frontend JS

React/Angular/Vue

Tools

TeamCity

Octopus Deploy

IIS

Job description

We are looking for a Senior Full-Stack .NET Developer experienced with both legacy .NET Framework and modern .NET (.NET 6/8+). The primary focus is security vulnerability remediation, legacy application support, and modernization.

Responsibilities

• Investigate and remediate application security vulnerabilities, including OWASP Top 10, SAST/DAST findings, SQL injection, XSS, and dependency risks
• Maintain and modernize legacy ASP.NET Web Forms, MVC, WCF, and ASMX applications
• Develop and enhance ASP.NET Core Web APIs and modern .NET services
• Work with SQL Server, ADO.NET, EF Core/Dapper, ensuring secure data access
• Support frontend development using HTML, CSS, JavaScript/TypeScript, jQuery, and modern SPA frameworks
• Collaborate with DevOps to support secure CI/CD and production deployments

Requirements

• 3+ years of full-stack .NET development experience
• Expertise in C#, .NET Framework, and SQL Server
• Proficiency in ASP.NET Web Forms and MVC
• Background in .NET 6/8+, ASP.NET Core, and REST APIs
• Understanding of dependency injection
• Practical application security experience and knowledge of OWASP Top 10
• Experience with React, Angular, or Vue.js
• Strong troubleshooting skills and ability to work with large legacy codebases
• English proficiency at an Upper-Intermediate level (B2) or higher

Nice to have

• Experience with TeamCity, Octopus Deploy, and IIS
• Knowledge of OAuth2, OIDC, and JWT
• Skills in HTML, CSS, and jQuery