The first stage was an informal chat with the recruiter. This was pretty straightforward and mainly consisted of the recruiter asking questions regarding my CV and then informing me of the interview process. The second stage was a system design interview with one of the co-founders. This was more intensive and consisted of being asked to design a system for a chatbot that compared mortgages for users given a query. The third stage was an on-site coding interview with a different co-founder which consisted of solving a proportional sampling algorithm that has order log(n) time and space complexity. Ultimately, this required applying binary search to the problem. The fourth stage was also on-site and was a behavioural interview with the COO. This consisted of being asked to provide examples in your life where you followed some of the company's core principles. I was asked about examples of "Fearless Innovation" and "Collaboration". The last stage would have been an offer. Unfortunately, I never heard back from them, despite being told they would reach out the next day. I even reached out to them multiple times, including an email CC'ing one of the co-founders, but never heard back. This is disappointing because it shows a complete lack of respect. Even if I wasn't suitable for the job, I spent my own time and energy preparing extensively for the interview, as well as my time and money travelling to London for the on-site interview. At the very least, I would have appreciated a quick phone call or even e-mail with feedback so that I can look to improve in the future. In general, although the co-founders seemed like smart and interesting people with a cool idea, the interview process as a whole was not good. This is largely because the recruiter was very unprofessional in their communication. For example, rather than emailing me, the recruiter added me on WhatsApp and used that as our primary mode of communication. On top of that, although I reached out multiple times after the fourth stage to figure out how I did, I never heard back from them.