ns10.pinterest.com has no CNAME records.
Question and response
Question
dig ns10.pinterest.com. NS
Answer
The response has no answer records.
Authority
pinterest.com. 1382 SOA ns5.pinterest.com. hostmaster.nsone.net. 1658264916 21600 3600 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0