C# is compiled to intermediate language, strongly typed, and garbage collected language. Let's abuse all these elements — we will emit machine code directly, abuse type system, override sealed types, hide objects from GC, all of that directly in the C# language without using external tools. We'll see real life scenarios where these things are used and that sometimes "one hacky line" saves us hours of debugging. Based on multiple examples, some are level 200, some are level 400, all of them are worth knowing about.