So I recently had an interview at a unicorn startup for a software developer position (SDE3 as I recall). I have about 5 years of experience, mostly in php and rails.

It was a programming round. They gave me a problem to code in about an hour. This was the problem (Imgur link) :

http://imgur.com/gallery/osqJx

It was expected that there shouldn't be any data loss.

I have no professional experience in Java, and my CV was quite clear on it.

Do I have to prepare myself for this kind of stuff? I’m not in the valley but is this the general expected standard? I was quite stunned that I had to code this in an hour, really wasn’t expecting this.