legacy-dotnet-patterns

name	legacy-dotnet-patterns
description	Patterns for building authentic .NET Framework 4.6 legacy applications (~2015 era)
domain	architecture
confidence	high
source	manual

Context

When building legacy .NET Framework applications that need to feel authentically era-appropriate (2013–2016). Used as the "before" state in modernization/migration demos.

Patterns

• Web API 2 with attribute routing ([RoutePrefix], [Route])
• Entity Framework 6 Code First with DbContext directly in controllers
• Unity IoC container registered in App_Start/UnityConfig.cs (but inconsistently used)
• Global.asax.cs for Application_Start with GlobalConfiguration.Configure()
• web.config for connection strings, app settings, IIS config — no secrets management
• Cookie-based auth via ASP.NET Identity 2.x
• MultipartMemoryStreamProvider for file uploads
• AngularJS frontend colocated in /app folder within the Web API project
• Bower for frontend packages, Grunt/Gulp for build (no webpack)
• IIFE pattern wrapping all Angular modules
• $http service for API calls, jQuery $.ajax for file uploads (mixed pattern)
• Bootstrap 3 panels, glyphicons, dl-horizontal for layout

Examples

• Controller: new PropertyProDbContext() in constructor (no DI for some controllers)
• Sync DB calls: _context.SaveChanges() instead of async
• File storage: byte[] → varbinary(MAX) in SQL Server
• Frontend routing: UI-Router states, not ngRoute
• Component pattern: .component() API (AngularJS 1.5+) with controllerAs syntax

Anti-Patterns

• Do NOT use .NET Core / .NET 5+ patterns
• Do NOT use ES modules or TypeScript
• Do NOT use Angular CLI or webpack
• Do NOT use repository pattern (keep it messy and coupled)
• Do NOT use ILogger or structured logging — use Trace or nothing
• Do NOT add health check endpoints
• Do NOT use Docker or containerization