They bought the search engine when it went bankrupt.
Still quite a feat and its results are actually better than ddg and bing.
"Today Brave announced the acquisition of Tailcat, the open search engine developed by the team formerly responsible for the privacy search and browser products at Cliqz, a holding of Hubert Burda Media. Tailcat will become the foundation of Brave Search..."
[0] https://blog.mozilla.org/press-uk/2017/10/06/testing-cliqz-i...