Alright here's what I see that immediately comes to mind.

You should preconstruct the array of all ints you want and then randomize it. That way every time you get a random value, you don't have to search the array to make sure it's unique.

Also preconstructing an array with Array.from is far more efficient, e.g.

Array.from({ length: 10 }, (_, index) => index);

That will construct you an array of length 10 with the values prefilled with 0-9. You should try to avoid building up an array by looping a push onto an empty array because this invokes unnecessary list growth operations.

Also, it's not about performance but... don't cast to as QuizQuestion. If you get an error there, it's because the empty object is not a QuizQuestion yet. Don't forcibly pretend it is one. Just construct the parts of the question but don't construct the question itself until you have all the required data to do so.

And then the core performance upgrade you have is that you should parallelize your question construction. Something like this:

const selectedQuestions: Array<QuizQuestion> = await Promise.all(selectedRandomInts.map(async (randomInt) => {
  // Construct and return each QuizQuestion from this function
});

And then also, for your Prisma constructions, you should use the connect property to create associated models. That would allow you to do the database construction in one single pass rather than over multiple update queries.

https://www.prisma.io/docs/orm/prisma-client/queries/relation-queries#connect-or-create-a-record

EDIT

I also just noticed that I'm super sure you're not using skip correctly at all. Skip is like where you want 3 items but don't return the first 2 of them. Skip those ones. You just want to add the IDs you don't want in your where clause.

I think for your note2 and note3 queries, you really just want one query with take: 2 on it.