Blog topic
ASP.NET Core DI lifetimes, registration habits, and factory delegates — how senior teams keep services testable and avoid captive dependencies.
Dependency injection in ASP.NET Core is easy to start and easy to get wrong. Most production bugs I see are not “forgot to register a service” — they are captive dependencies (a Singleton holding a Scoped DbContext), hidden new-ups that bypass the container, or factory delegates that close over request state. This hub collects the DI notes I use on healthcare, SaaS, and marketplace APIs: lifetimes, registration habits, and how Factory-style delegates fit when a switch statement is really a composition problem. Read the lifetimes article first if you own Program.cs. Pair it with Factory or Strategy posts when the container is being asked to pick an implementation at runtime. The goal is a container graph a teammate can explain in a PR, not a clever service locator.
4 min read
How I use AddKeyedScoped and FromKeyedServices in ASP.NET Core for closed sets of implementations — EDI vs FHIR clients, tenant notifiers — and when a factory is still the honest design.
7 min read
ASP.NET Core dependency injection explained for real apps — Singleton vs Scoped vs Transient, captive dependencies, factory registration, and habits that keep .NET APIs testable.
8 min read
How to use the Factory Pattern in C# with ASP.NET Core DI — replace brittle switch statements, use factory delegates and keyed services, and know when a real factory class is worth it.