Do you know if there are common tools people use as a search engine backend for this? Vespa.ai seems promising, although I can't tell if there are many people using it.
* CNN (plenty of pre-trained * Approximate Nearest Neighbors Database (Annoy, etc) * webserver to host CNN and serve UI
It's popular to serve tensorflow models w/ tensorflow severing + kubernetes and that's what' I've done in the past.