I applied through an employee referral. The process took 3 weeks. I interviewed at Pinterest in Dec 2017
Interview
The first step was a coding challenge to be completed within 12 hours. I was told I passed that test and then came a machine learning interview where they asked basic questions about a machine learning problem carried out from end to end.
Interview questions [1]
Question 1
The coding challenge questions were: find objects in an image (2 or more black pixels together), an sql querry, and a pinterest api question.