Lead .NET Consultant – Application Modernization

About The Opportunity

We are looking for a Lead Consultant with deep expertise in Microsoft .NET to drive the technical execution of application migration and modernization initiatives.

In this role, you will be responsible for migrating legacy .NET Framework applications to .NET 8+ on Linux, designing and implementing solutions for complex porting scenarios, and ensuring applications are ready for deployment in AWS environments.

You will work hands-on across application modernization, cloud deployment, data access, testing, automation, and troubleshooting. The role also involves leveraging AI-assisted development and agentic AI tooling to accelerate migration activities while maintaining high standards of code quality and reliability.

The ideal candidate combines strong software engineering fundamentals with extensive experience in C#, ASP.NET, .NET Framework, .NET Core, AWS, microservices, and application modernization.

Responsibilities

• Lead the migration of .NET Framework applications (C#, ASP.NET) to .NET 8+ running on Linux.
• Analyze legacy applications and identify technical challenges, workarounds, and edge cases during migration.
• Develop automated and repeatable solutions for common migration and modernization issues.
• Modernize application components while maintaining functionality, performance, and reliability.
• Convert ASP.NET WebForms interfaces to Blazor, leveraging AI-assisted development when appropriate.
• Modify and modernize data access layers using ADO.NET, Entity Framework, and Dapper.
• Adapt data access implementations for modern platforms and databases, including PostgreSQL/Npgsql.
• Deploy and troubleshoot migrated applications on AWS EC2 Linux.
• Work with AWS services such as EC2, S3, RDS, Lambda, IAM, VPC, CloudFormation, CDK.NET, and AWS SDK for .NET.
• Design and execute test plans and test cases to validate application readiness after migration.
• Perform confidence testing to ensure applications compile, start, and operate correctly in Linux environments.
• Use code scanning and assessment tools to analyze legacy codebases, identify migration risks, and estimate modernization effort.
• Leverage agentic AI tools to accelerate application porting while reviewing, validating, and correcting AI-generated code.
• Work with engineering and professional services teams to support technical proposals and ensure smooth project handovers.
• Collaborate within Agile teams and contribute to automated build, test, and deployment pipelines.
• Apply performance optimization techniques to ensure modernized applications meet expected scalability and performance requirements.
  
  

Required Qualifications

• 10+ years of professional software development experience.
• Strong hands-on expertise with:C#, .NET Framework 4.6–4.8, .NET 8+ /, .NET Core on Linux, ASP.NET, Web API, WCF, ADO.NET, Entity Framework,Dapper.
• Proven experience migrating and modernizing .NET Framework applications to .NET Core/.NET 8+.
• Ability to independently read, navigate, modify, build, troubleshoot, and validate existing .NET Framework and .NET Core applications.
• Strong understanding of ASP.NET WebForms and Blazor, including the ability to modernize WebForms applications into Blazor.
• Experience identifying and resolving NuGet package compatibility issues and selecting appropriate .NET Core/.NET alternatives.
• Hands-on experience with AWS, particularly: EC2, S3, RDS, Lambda, IAM VPC, CloudFormation, CDK.NET, AWS SDK for .NET
• Experience deploying and troubleshooting .NET applications on EC2 Linux, including systemd, permissions, application startup, and runtime troubleshooting.
• Strong experience developing and supporting microservices-based applications using containers.
• Experience with Agile software development methodologies.
• Experience with automated CI/CD build, test, and deployment pipelines.
• Strong understanding of software testing and the ability to develop test plans and test cases for application validation.
• Strong Git experience, including cloning repositories, branching, committing, pushing changes, and creating pull requests.
• Strong problem-solving and troubleshooting skills.
• Excellent communication and collaboration skills.
• Ability to work independently and take ownership of technical challenges.
  
  

Nice To Have Skills

• AWS Certified Solutions Architect – Associate or AWS Certified Developer – Associate.
• Experience with Blazor component development and modernization of legacy WebForms applications.
• Experience with PostgreSQL and Npgsql.
• Experience using PowerShell 7+ for automation and codebase analysis.
• Experience with automated codebase scanners and migration assessment tools.
• Experience using agentic AI / AI-assisted development tools for application modernization and code migration.
• Experience with tools such as Kiro, Q, or ATF.
• Experience reviewing and correcting AI-generated code in production-oriented applications.
• Strong knowledge of application performance optimization and troubleshooting.
• Experience with large-scale enterprise application modernization projects.
• Experience preparing technical proposals, solution approaches, or project estimates.
• Experience working with distributed teams and client-facing technical stakeholders.
  
  

Avenue Code reinforces its commitment to privacy and to all the principles guaranteed by the most accurate global data protection laws, such as GDPR, LGPD, CCPA and CPRA. The Candidate data shared with Avenue Code will be kept confidential and will not be transmitted to disinterested third parties, nor will it be used for purposes other than the application for open positions. As a Consultancy company, Avenue Code may share your information with its clients and other Companies from the CompassUol Group to which Avenue Code’s consultants are allocated to perform its services. Show more Show less