By all means, stay away from this company! You will be 100% clear on why when you reach the end of this paragraph. I was invited to a phone interview after reaching out to them (I had met them at a career event). I had the phone interview a month after making contact with them. It should have been one hour long and went on for 10 mins more they had said when I asked them about the duration, it was thorough with questions about myself and my skillset, with little space for me to ask questions. This was followed by a F2F interview at their office about a month after the first interview. This overran by 40 mins with respect to the duration that I was told (again, after asking explicitly), which was very unprofessional by them. They wanted to know a lot more about me and my technical skills (this was followed by usual personal experience interview questions) compared to the phone interview. I filled two blackboards with Maths formulae and got to know more about the company after signing an NDA (required before the interview started). First part with two researchers, I enjoyed it and they seemed nice, serious and prepared (but overran with times), second part with HR. Now the terrifying bit. I was offered a job and sent offer letter and contract, they were both WITHOUT any signature by anyone from nChain. After negotiations they sent the same documents, simply putting in the start date, again no document was signed by them. I returned them promptly with my signatures (and a witness’). I asked why no signatures from their side, they replied “for security reasons”, and I said that before resigning I needed them to fix this. The day after they withdrew their offer of employment to me!!! I had nearly resigned, especially because they (researcher + 2 ppl from HR) had reassured me that everything was fine and I shouldn't worry, they simply needed my references that they are legally obliged to do before employing someone bla bla bla. Apparently (their words) their standard procedure is to show the contract to the new employee on his/her first day of employment, for the first time. If they are “lucky” to get there. Round of applause!