API Gateways - any experience with Kong, Boomi, Gravitee, Apache APISIX, Tyk, etc.?

Hi All, I just did a search for "API Gateways" (yes, I enclosed with quotes) in these forums and was surprised to get zero results back :) I have the potential opportunity to monetize some data that I hold in a MariaDB database, so I'm just starting down the path of understanding how best/easiest to make this happen. For example, an article like this looks very interesting!