The first stage involved a discussion with a recruiting manager over the phone (not a technical discussion). The next stage involved a technical screening through a website called Hacker Rank.

I was given a problem to solve and a time limit to solve it, and was asked to improve the efficiency of my solution as I developed it.

They asked me to sift through a list of elements and extract all pairs of elements that satisfied a given condition (namely, the difference between the two had to be a certain value). I was required to solve this in code.