Cloudflare Systems Reliability Engineer interview questions

I applied for CloudFlare online, and the next day was contacted by a Hiring Manager for a phone screen, where I was able to further clarify the position - the online job description seemed to list more responsibilities under the requirements section, leading to a bit of confusion around what the job actually involved. After this screening, I was contacted to set up a technical interview. Initially this was to be over the phone, however it was later organised to be over Skype - a leniency which I was thankful for, in my experience technical interviews over a phone are not easy for either party. This technical interview was mostly standard Linux debugging (strace, netstat, ps, the /proc tree etc) and Networking (How does making an Web Request work, DNS stuff). We then went through a few debugging scenarios, which were very D&D esque - you see this, what do you do. I believe this interview was more to gauge problem solving more than anything else. About a day after this interview I was contacted to set up a call with the Engineering Manager. This call was a rather straight forward managerial interview - why CloudFlare, how would you describe CloudFlare's business, why should we select you etc. After that interview, we organised an onsite interview in CloudFlare's London office. This took a couple of weeks - understandable considering the difficulty in wrangling peoples schedules, and the hiring team were very gracious when I asked to reschedule. The onsite interview was a day long and consisted of a technical interview (which was very well done - it's done as a series of problems to solve on a throw away digital ocean droplet), an interview with two other members of the team (mostly talking about my background, with a few other technical questions thrown in for good mix), an interview with a couple of people from the network engineering team, and then a final debrief with the engineering manager. During this, I also went to lunch with a couple of the engineers I would be working with which was an enjoyable experience. From the on site interview, everything worked exceedingly quickly. About half an hour after I stepped out of the office I received an email asking for my availability for phone conversations over the next week, and over the course of the week I had phone conversations with the head of operations and the CEO who helped clarify any of my last questions about the company. Two days following these conversations, I received an offer which I gladly accepted. The one thing that baffled me was the use of phone conversations. The process would be well served with a move onto a VoIP system like Hangouts or Skype - especially for technical interviews. The one phone technical interview I did have, I organised with the interviewer to perform it over Skype however. At least there is some flexibility. Throughout the process I was kept in regular updates by the hiring manager as to where the process was going, and I was thoroughly impressed with the entire process.