I applied online, and was contacted the same day by an internal recruiter. After an introductory call, I was scheduled for a one-hour video technical interview with an engineering manager.
The initial interview was more about assessing my technical knowledge, as well as my experience, and did not have a coding component. It touched on some principles involved in both backend engineering and frontend engineering.
After that, I moved on to a one-hour video coding interview with an engineer. Unlike some other technical interviews I've done, there wasn't much ramp-up to get to know one another, and we jumped straight into the problems. We didn't use HackerRank, it was bring-your-own IDE (I used RubyMine, but you could use repl.it, or something else if you'd like). I would describe the difficulty of the problems as easy, maybe medium.
After that, there was a one-hour video interview with the director of full-stack engineering. This was more a mix of questions related to behavior and technical experience/principles.
Finally, there was a 30-minute call with the CTO. The CTO was very nice, and basically left this call open for discussion about anything. He talked a lot about Wurl and its growth, and where he envisions the company going. It was insightful, and it was great to get to have a good conversation with him for 40 minutes (we stayed on for a bit after the scheduled block to keep talking).