It's a little buried, but here's the primary tldr of their KSUID library:
> Thus KSUID was born. KSUID is an abbreviation for K-Sortable Unique IDentifier. It combines the simplicity and security of UUID Version 4 with the lexicographic k-ordering properties of Flake. KSUID makes some trade-offs to achieve these goals, but we believe these to be reasonable for both our use cases and many others out there.
> Thus KSUID was born. KSUID is an abbreviation for K-Sortable Unique IDentifier. It combines the simplicity and security of UUID Version 4 with the lexicographic k-ordering properties of Flake. KSUID makes some trade-offs to achieve these goals, but we believe these to be reasonable for both our use cases and many others out there.