Registration Onboarding Flow

I was wondering if we could ask a patron at the time of signing up to pick any 3 subjects that they would be interested in. Since the trending books only reflect the general readers and may not fit well to the needs of readers with interests that do not fall in the average set. This would ensure that the new patrons get a more relevant feed. Spotify and Medium do this for new users.

A "Trending in {Subject}" feed is what I am thinking of. We could use the trending API and filter the results by the patron's subject of interest. If there is no book trending in that Subject, then we simply do not display its section until there is one.

The philosophy behind this is to make a new patron engage with the new environment via means of familiarity (through interested Subjects), making the initial action of reading their first book on the platform easier.

However on the flipside of it, we will loose our current one-step sign up process. Perhaps this might need some weighing of the pros and cons.

Thanks!

TL;DR
Ask new patrons for their subjects of interest at sign up and show the trending feed based on the interested subject.
Pro - will help readers find the first book they will read on the platform more easily
Con - we loose our one-step sign up process.

_Originally posted by @Spaarsh in https://github.com/internetarchive/openlibrary/issues/10242#issuecomment-2567130849_

No files, tests, or entry points are named. Start by locating the registration flow and trending-feed implementation, then determine how subject preferences would be stored and applied. Done should include an agreed onboarding design, subject-based trending sections, and a decision on whether the one-step signup tradeoff is acceptable.

Written by the indexing model from the issue text.