WhatsApp Software Developer interview questions

It came with an interview about your resume and past experiences at first. Then it was followed by two technical phone screens. Finally, there was an on-site with 4 interviews. The final one was held by one of the co-founders.

Dropped off resume and answered a quick easy coding question at my university's career fair. The question was to implement a string reversal in any language. I did it in one line in python. Received an email that same day/night inviting me to interview on my university's campus with them the following day. Harder than a standard interview I thought.