BenchmarkDotNet is a powerful .NET library for benchmarking. Benchmarking is really hard (especially microbenchmarking), you can easily make a mistake during performance measurements. BenchmarkDotNet will protect you from the common pitfalls (even for experienced developers) because it does all the dirty work for you.
hashids (Hash ID's) creates short, unique, decryptable hashes from unsigned integers. It was designed for websites to use in URL shortening, tracking stuff, or making pages private (or at least unguessable).