A really nice feature of routing in ASP.NET Core is inline route constraints. Useful URLs contain more than just paths, they have identifiers, parameters, etc. As with all user input you want to limit or constrain those inputs. You can unit test your custom inline route constraints as well.
C# 7.0 is the next version of C#. This article provides an overview of the current state of thought process involved while designing new C# 7.0 features.
According to Phil Karlton there are only two hard things in Computer Science: cache invalidation and naming things. This article covers the latter and gives good advice for naming variables.
Check out this live visualisation of the .NET GC in action. It's a follow up to an excellent article on how a Garbage Collector works.