The whole process is very lengthy - definitely the longest interview process I've ever been through. Overall there were 4 stages:
1. Initial phone call with a recruiter (30 minutes)
2. Take home tech task (~3 hours)
3. Technical interview and pair programming task (1 hour), followed by a cultural interview (1 hour)
4. Separate interviews with the head of engineering (30 minutes), head of digital product (30 minutes), and one of the founders (1 hour)
Most of the people I spoke with were very welcoming and easy to talk to. The tech task was fairly straightforward, although it definitely took longer than 3 hours especially since some test coverage was expected. The tech interview and the pair programming task were also reasonable and straightforward, and although the nerves got to me the interviewers were very understanding and helpful.
After getting through stage 3 and receiving positive feedback in all the stages I felt that this is where a decision could have been made; if you think a candidate is a good cultural fit, has the technical skills, and they "#striveforbetter", then stage 4 feels quite unnecessarily excessive.
The interviews in stage 4 were basically just repeated/reworded questions from the cultural interview in stage 3 (I found that I had to repeat myself quite often throughout the whole process), except for the interview with one of the founders; this interview felt cold and awkward, and the questions were mostly unorthodox "what would you do if" scenarios that were seemingly read straight from a screen back to back for almost a full hour with no real structure or natural flow. One of the other interviewers also turned up almost 15 minutes late and sped through the other 15 minutes we had left. Upon completing this stage the feedback I got strangely contradicted the feedback from the previous stages, and the conclusion was that "they're not sure I care about the impact of my work" which is not constructive or informative at all. This stage completely soured my overall experience.
Overall I met some very nice, ambitious people with a great mission. However, expecting candidates to go through >7 hours of tasks/interviews is quite extreme, especially when the same questions are basically repeated throughout the whole process. I think an excessive interview process says more about a companies analysis paralysis, inability to trust, or inherent obfuscation of what their ideal candidate appears to be, whether in person or on paper.