An endpoint in my ASP.NET Core web API project suddenly started returning a truncated JSON response with a 200 response code. According to the logs, an exception was thrown, but for some reason the response code was not 500 as I would expect.
With the new System.Text.Json built into .NET Core, JSON serialization can now be performed without the Json.NET library. However, there are differences between the two libraries once you go beyond the basics. For example, support for serializing and deserializing polymorphic objects is limited in the new library.
XmlSerializer is often a great choice for persisting objects or transmitting them over the wire, either by using default object serialization tailored only with attributes or by implementing the IXmlSerializable yourself. If you're not careful though, this might come at a significant performance cost.
Recently I tackled a seemingly simple task: XML serialization of a generic class used with a TimeSpan data type. It turned out that XmlSerializer doesn't serialize the TimeSpan structure at all.