I applied through the website (without a referral). It took around one month and a half, but to be honest, it was my fault because my schedule was full. The process had 5 steps and all of them was remote.
The first task was an app that calculates the total price of an inventory that I had to retrieve from Shopify API (It's relatively easy) but they gave us poor information, I think that it was on purpose.
After that, I received an email that they wanted to contact me. After arranging a call with one of their recruiting staff, I was asked about my Life Experience, my projects, my studies, my experiences, and so forth.
One week later I received an email saying that they wanted to arrange a call with two team leaders of their team (I choose a particular technology so I had the interview with the team of that technology). In this interview I was asked about my experiences about the technology, designs patterns and problems that they had in the development process. I was asked how I would tackle those problems. It is about one hour. It's medium level of interview since I have experience with the technology I could reply most of the questions, however other questions were very difficult and I had ideas.
After this call, I had to wait one or two weeks to heard from them. I received a message to arrange a new meeting with one different developer. He was an expert about the technology. To be honest I was asked questions that are for a Senior or Semi-Senior developer. These are not easy questions, but all the questions are available in most of the books that talk about the technology. This was the hardest interview, and the last one. After all, the interviewer was so cool, he tried to stay me calm, very kind and polite. The interview took about 1:15 hour.
After two weeks I got the offer from the recruiter that guided me through the process.
In summary, it is a medium-hard interview. Different to other companies, but I like so much.
Hints to applicants: Have clear ideas about why would you like to work on Shopify, and which technology/area you would like to work. After decide that you should focus on the technology. Also, take into account that you will be asked about patterns and things that are not dependent on one technology.