Hopper takes interviewing seriously and doesn't waste time, which makes for a positive experience regardless of the outcome.
I applied online, not knowing much about the company or knowing anyone working there. I got a prompt reply asking me to complete a short programming puzzle. I got invited for an onsite screening a few days later, which was half whiteboard coding test, half get-to-know-each-other, nothing unusual. Then came a full-day onsite which was more of the same, soon followed by a decision and an offer.