serialization

1# Serialization in .NET
2 
3## When to Use This Skill
4 
5Use this skill when:
6- Choosing a serialization format for APIs, messaging, or persistence
7- Migrating from Newtonsoft.Json to System.Text.Json
8- Implementing AOT-compatible serialization
9- Designing wire formats for distributed systems
10- Optimizing serialization performance
11 
12---
13 
14## Schema-Based vs Reflection-Based
15 
16| Aspect | Schema-Based | Reflection-Based |
17|--------|--------------|------------------|
18| **Examples** | Protobuf, MessagePack, System.Text.Json (source gen) | Newtonsoft.Json, BinaryFormatter |
19| **Type info in payload** | No (external schema) | Yes (type names embedded) |
20| **Versioning** | Explicit field numbers/names | Implicit (type structure) |
21| **Performance** | Fast (no reflection) | Slower (runtime reflection) |
22| **AOT compatible** | Yes | No |
23| **Wire compatibility** | Excellent | Poor |
24 
25**Recommendation**: Use schema-based serialization for anything that crosses process boundaries.
26 
27---
28 
29## Format Recommendations
30 
31| Use Case | Recommended Format | Why |
32|----------|-------------------|-----|
33| **REST APIs** | System.Text.Json (source gen) | Standard, AOT-compatible |
34| **gRPC** | Protocol Buffers | Native format, excellent versioning |
35| **Actor messaging** | MessagePack or Protobuf | Compact, fast, version-safe |
36| **Event sourcing** | Protobuf or MessagePack | Must handle old events forever |
37| **Caching** | MessagePack | Compact, fast |
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