So, I just interviewed for a job, and is in final stages. I met with co-workers, HR, and the hiring manager likes me. (I don't know if they're evaluating other candidates, but I am definitely in the mix for considerations.) I think there will be one more round of meeting the owner.

But, at this point, they are asking for references. I prepared references, but they asked for 15-20. I didn't prepare 15-20 references, more like 5.

I'm on the fence on this opportunity. I think the work is interesting, but I think there are some downside on commute and work/life balance.

So, while I'm interested in moving along the conversation to see where it goes, I don't know if I can find 15 people to vouch for me (I have been in my company actually for a while and don't want to rock the boat till I actually landed somewhere. And they were clear that they want professional references, so family members are out.

What are your thoughts? I find 20 references to be excessive. Since I'm on the fence, should I pass and not hassle my contacts?

Any advice welcomed

I agree its excessive, 3-5 is common. Plus if someone agrees to be a reference they can usually be counted on as a positive so checking references usually doesn't get much.

Give them 5. 15 to 20 is unheard of. Attach a note (or tell them) that you are not prepared to give more because you have not told anyone at your current job yet, and won't until you have this job.
It's almost like they are new and clueless? I don't get it.

I've never seen an employer ask for 20 before.. ever.. and I've worked for 7 different employers in the past.30+ decades but if they are asking for 20 you really do want to give them 20, who knows that might be the one factor that sets you apart from someone else they like equally well but only finds 5.. You should be able to find 20 people you used to work with or for assuming you have previous work experience.

Excessive yes... but they hold all the cards. And its not something that should be a deal breaker.