Maker here. I've put together several custom search engines that helped me fight poor Google search performance on certain queries. The search engines use Google Custom Search Engine configured for selected websites and return succinct results on general queries, especially the queries attracting SEO spammers.

The engines are listed on https://searchcommons.org/engines.html and here are some of them:

— The web minus Alexa top 1000 most visited websites https://searchcommons.org/?e=most-visited-websites-excluded

— Official docs for Python and its libraries https://searchcommons.org/?e=python-docs (feel free to request an engine for your programming language)

— Universities with Nobel Prize, Fields Medal, and Turing Award laureates https://searchcommons.org/?e=universities-with-laureates

The lists of selected websites are public and open to contributions: https://github.com/antontarasenko/searchcommons