As a corollary, are there any good libraries for helping build more complex onboarding flows, or do these all tends to be hand-built from scratch? I've seen a

As a corollary, are there any good libraries for helping build more complex onboarding flows, or do these all tends to be hand-built from scratch? I've seen a few javascript walk-through tour type libraries, but what about something that integrates with a backend to be stateful on what a user has done?