Скачать или смотреть Refactoring SSE for Real-Time Job Progress - .NET Job Importer

Building a PDF import system with real-time progress updates. This video focuses on refactoring the Server-Sent Events service that streams job progress to the client.

The original code worked but was a 400-line mess - static dictionaries, magic strings everywhere, SSE formatting mixed with business logic. Untestable.

I break it into clean, focused pieces:

SseEventTypes - no more magic strings
ISseWriter - SSE formatting extracted behind an interface
IStreamRateLimiter - thread-safe rate limiting with enum results instead of stringly-typed errors
IImportJobPoller - managed DbContext lifecycle for long-running polling loops

Each piece can be unit tested in isolation, mocked when testing the service, and swapped out for different implementations.

Next video: implementing the inbox pattern with MassTransit to actually process the PDF imports. Then we test the full flow - upload files, watch events stream in real-time.

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Tech stack:
.NET 9
Entity Framework Core
Server-Sent Events (SSE)
MassTransit (coming next)
TanStack Start frontend

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Part of the Job Importer series - building a complete file import system with background processing and real-time updates.