I'll never have enough imagination to believe mongo is a good solution. Postgres has jsonb, vector type; redis is a fine-enough cache. Why use a known junk "database" when there are superior solutions and truly open source?
I didn’t say you have to use it. I said you could. Or any other data store that fits your use case. I used a MongoDB instance back in 2012 in a serious production environment in this exact way and it worked flawlessly while Postgres was what gave us trouble (it had a bunch of features added since that would have made those issues disappear but back then it didn’t have built in replication for example.)
But again this is not an endorsement of MongoDB. I wouldn’t use it today but I did use it successfully and that company and tech stack sold for quite a bit of money and the software still runs, though I’m not sure on what stack. Again, if you are stuck on this one part of my comment… can’t help you.
