I want to do my own version of something like this to have a personally curated search function. The "it's mine" factor is enticing, if it does something unexpe

I want to do my own version of something like this to have a personally curated search function. The "it's mine" factor is enticing, if it does something unexpected, then I know all the dependent, interacting parts so I can trace the problem and fix it. But I'm a privacy and self-hosting nut, which is probably just another way of saying the same thing. (I will probably never actually do it, but that doesn't stop it being on the list).