DDG has been around for a long-long time, and when it started Perl was an old fashioned choice but still very reasonable. Even if they moved to other languages they probably still have old bits of Perl code running somewhere.

For about first 5-10 years of its existence DuckDuckGo also promoted their use of Perl, and afaik they contributed to Perl development.

I applied with twenty years experience + with perl and was unceremoniously denied quickly. Looking for unicorn or ghost job, take your pick.