[ditsuke]

DDG uses Bing (like most other alternative search engines). I believe Brave's new search engine uses its own index though.

[merlinscholz]

Exactly, they use their own index, which AFAIK can be seeded by other search engine results. Here's an overview: https://support.brave.com/hc/en-us/articles/4409406835469-Wh...