A .NET component discovers handlers with reflection and attributes. What are the benefits and risks, especially when the application is trimmed or Native AOT compiled?

Reflection and attributes under trimming and AOT

Uses metadata-driven behavior deliberately and protects reflection-dependent code when publishing with trimming or ahead-of-time compilation.

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Attributes attach metadata to program elements; reflection reads that metadata and inspects types or members at runtime. This can support plugin discovery, serialization, validation, or mapping without hard-coded registration. The cost is more runtime work, weaker compile-time guarantees, and failures that appear only when a type or constructor is missing. With trimming or Native AOT, code reached only through reflection may be removed because static analysis cannot prove it is needed.

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Reflection, attributes as metadata, discovery cost, explicit registration, caching, trimming, source generation, and Native AOT compatibility.

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Reflection can remove repetitive registration code, but it creates a runtime dependency that the compiler and linker may not be able to see. Deployment mode turns that convenience into a correctness boundary.
Attributes attach metadata to program elements; reflection reads that metadata and inspects types or members at runtime. This can support plugin discovery, serialization, validation, or mapping without hard-coded registration. The cost is more runtime work, weaker compile-time guarantees, and failures that appear only when a type or constructor is missing. With trimming or Native AOT, code reached only through reflection may be removed because static analysis cannot prove it is needed.
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For a bounded set of handlers I prefer explicit registration or a source generator that produces registration code at build time. If runtime discovery is appropriate, I scan a known assembly and contract rather than every loaded type, validate duplicates and constructors at startup, and cache the resulting delegates or descriptors. Repeating , , or on every request adds avoidable latency and allocation. Attribute presence also does not enforce behavior by itself; some component must interpret it consistently.

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Scanning every loaded assembly on each request instead of building a startup registry.
Assuming an attribute automatically enforces the behavior it describes.
Suppressing all trimming warnings without identifying dynamically required members.
Testing reflection discovery only in an untrimmed development build.

A .NET component discovers handlers with reflection and attributes. What are the benefits and risks, especially when the application is trimmed or Native AOT compiled?

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