There's an official thread on the 1st of every month submitted by a bot -

April posts:

1) who's hiring: https://news.ycombinator.com/item?id=9303396

2) who wants to be hired: https://news.ycombinator.com/item?id=9303599

3) freelancer & seeking freelancers: https://news.ycombinator.com/item?id=9303589

The bot itself, although april was submitted by a different account afaik cause of a DST changeover glitch:

https://news.ycombinator.com/submitted?id=whoishiring