Senior .NET Modernization Lead (EDI Domain)

Role Summary

The Senior .NET Modernization Lead will provide technical leadership for application discovery, architecture assessment, knowledge acquisition, and modernization planning of a large-scale legacy .NET platform. This role is responsible for validating the existing application architecture, identifying dependencies, conducting technical assessments with engineering teams, and defining the future-state technical architecture. The individual will also guide engineering teams by establishing modernization strategies, architectural principles, and migration approaches for enterprise-scale applications.

Key Responsibilities

• Lead technical discovery, architecture assessment, and knowledge acquisition activities across a large-scale legacy .NET platform.
• Conduct architecture reviews, technical interviews, and code walkthroughs with architects, developers, product owners, and subject matter experts.
• Map the complete .NET Framework monolith dependency graph across desktop applications, web applications, backend services, databases, and external integrations.
• Validate and enrich existing architecture documentation by identifying undocumented dependencies, architectural patterns, and technical risks.
• Analyze EDI transaction processing, trading partner integrations, mapping workflows, acknowledgement processing, and backend integration services.
• Ensure dependency mapping includes end-to-end EDI transaction flows, trading partner touchpoints, acknowledgement workflows, and associated business processes.
• Assess application architecture, scheduler framework, integration patterns, database architecture, engineering practices, and technical debt.
• Define a high-level future-state technical architecture, including target application architecture, integration patterns, scheduler architecture, API strategy, engineering platform, and supporting Azure-native technologies.
• Develop modernization strategies using incremental migration approaches such as the Strangler Fig pattern to safely decouple legacy components.
• Define migration sequencing to progressively separate presentation, business logic, integration services, and database dependencies.
• Evaluate and recommend modern frontend technologies and architecture for legacy WinForms, WPF, Web Forms, and ASP.NET applications.
• Identify opportunities to improve scalability, maintainability, performance, security, and extensibility through modern engineering practices.
• Provide technical leadership to engineering teams by establishing architectural standards, modernization principles, and implementation guidance.

Required Skills & Experience

• 12+ years of experience designing and developing enterprise applications using Microsoft technologies.
• Deep expertise in .NET Framework 4.x, ASP.NET Web Forms, MVC, WinForms, WPF, C#, and SQL Server.
• Strong experience modernizing large-scale monolithic enterprise applications.
• Extensive experience with Azure cloud-native architecture, including Azure App Services, Azure Kubernetes Service (AKS), Azure SQL, Azure Storage, Azure Service Bus, Azure Functions, Azure API Management, and related Azure services.
• Strong understanding of application dependency analysis, architectural decomposition, and incremental modernization strategies.
• Experience designing modern frontend architectures using Angular, React, Blazor, or comparable frameworks.
• Strong database architecture and SQL Server performance optimization experience.

EDI Domain Expertise

• Deep understanding of EDI platforms, B2B integration, and enterprise transaction processing.
• Experience with ANSI X12, EDIFACT, trading partner onboarding, mapping, routing, validation, and acknowledgement processing (997/999).
• Strong understanding of mapping engines, integration middleware, backend processing workflows, and end-to-end business transaction flows.
• Ability to analyze complex EDI architectures and identify modernization opportunities while minimizing business disruption.