I applied online. The process took 1+ week. I interviewed at Mozilla
Interview
A week after I submitted my application online, I got an email informing me to take a hackerrank test. They questions were pretty straightforward. However, I didn't know what to expect and so wasted too much time on the first question that I didn't finish the last one.
Interview questions [1]
Question 1
There are 3 questions. All in JavaScript. They are about data structure, asynchronous io and DOM manipulation.