window application to Web migration suggestion required

As you are already a Windows developer familiar with C# and Visual Studio, so sticking with .NET Core and Blazor keeps the learning curve manageable.

Frontend (User Interface)
ASP.NET Core with Blazor:
Blazor allows you to build interactive web UIs using C# (your familiar language) instead of JavaScript. It comes in two flavors:
Blazor Server: Runs on the server with real-time updates over SignalR. Good for apps with simpler scaling needs.
Blazor WebAssembly: Runs in the browser, giving a more modern SPA (Single Page Application) feel. Ideal if you want offline capabilities or high client-side performance.
Why? You won’t need to learn JavaScript extensively, and it integrates seamlessly with .NET Core.
Alternative: ASP.NET Core MVC with Razor pages if you prefer traditional server-side rendering with some JavaScript for interactivity. This might feel closer to WinForms' form-based mindset initially.
Backend (Business Logic)
ASP.NET Core:
This is the modern, cross-platform evolution of .NET. It’s lightweight, fast, and supports APIs, which are crucial for a web app. You can reuse a lot of your existing C# business logic here.
Use RESTful APIs or gRPC (if performance is critical) to connect your frontend to the backend.
Database
Stick with your existing database (e.g., SQL Server, if you’re already using it with WinForms). ASP.NET Core integrates well with Entity Framework Core for data access, which simplifies CRUD operations.
Additional Tools
CSS Framework: Use Bootstrap or Tailwind CSS for responsive design. This will make your app look modern and work well on different devices.
JavaScript (Optional): For small UI enhancements, you might need basic JavaScript (e.g., jQuery), but Blazor can minimize this need.
Authentication: ASP.NET Core Identity for user management, roles, and security.
Hosting: Azure, IIS, or a Linux-based server (since .NET Core is cross-platform).

You can segregate fornt end and back end.

Front End - go for Angular or React

Back end - .Net Web API.

Plan for  modular monolithic.

Firstly, it won't be simple, and you need huge development/QA effort for this migration. 

I would suggest to modular approach. You can convert backend as API and Front end - Any popular front end (Angular or React). 

You can start with a module and convert the backend as API where you can use same winforms as front-end, then convert winforms to web EF.

With one module as POC, you can get idea about time and complexity. Plan accordingly. Better outsource some development, to get it done quickly. 

Migrating a large WinForms ERP application to a web-based platform is a significant undertaking! Here are some clear suggestions tailored for your situation:

1. Technologies to Use

• Frontend:

  • React or Angular for building responsive user interfaces.
  • Blazor (if you prefer staying within the .NET ecosystem) allows you to use C# for the frontend.

• Backend:

  • ASP.NET Core: A powerful, cross-platform framework for building web applications and APIs.

• Database:

  • SQL Server or PostgreSQL (if you want an open-source option).

• Hosting:

  • Consider cloud platforms like Azure, AWS, or Google Cloud for scalability.

2. Development Environment

• Visual Studio:
  • Use Visual Studio for development, as it supports both ASP.NET Core and various front-end frameworks.
  • If you're familiar with Visual Studio, it can ease your transition to web development.

Additional Tips:

• Incremental Migration: Consider gradually migrating forms rather than all at once. This can help manage complexity and reduce risk.
• Responsive Design: Ensure your new web application is mobile-friendly.
• User Training: Prepare for user training, as the interface and interaction will differ significantly from WinForms

Migrating a window application to the web can be a challenging task, but it's definitely worth the effort in the long run. It’s important to start by assessing the current architecture and then plan the migration in phases to ensure minimal disruption. One great approach to building a solid web application is by looking into frameworks and tools that suit your needs. If you’re thinking about a more customized solution, building an erp from scratch can provide valuable insights on how to structure and develop your web application efficiently. Don’t forget to factor in testing and security throughout the migration process.