There are more technical details here: https://duck.co/help/results/yahoo-techn...
In summary, the server is owned and operated by DuckDuckGo, to comply with our privacy policy, and the domain is delegated by Yahoo through DNS. This can be verified at the command line by checking the CNAME record using:

dig duckduckgo-owned-server.yahoo.net
posted by tagawa Staff2 years and 7 months ago Link