I applied through Hired.com and Ocado's recruiter followed up with an invitation to the online test within 3 weeks. Having prior embedded development experience, I was only required to complete logical reasoning test online before ultimately being invited to Ocado Technology office in Welwyn Garden City few weeks later. The interview day at Ocado was very relaxed. It was immediately apparent that this is their engineering office, not a customer-facing site - there was no reception and the recruiter was in their headquarters in Hatfield, not in WGC office I went to. The atmosphere in the office seemed friendly and it had that nice "start-up feel" about it. I was asked to take one of their unoccupied desks to complete the written test. Written test presented me with imaginary, assembly-like programming language consisting of 4 instructions (ZERO, ASSIGN, INCR and LOOP). Over 10 questions of varying difficulty required me to write code using these instructions to complete more complex tasks (some of them were, as described by others: ADD, DECR, SUBT, MULT, MAX, MIN, GREATER, LESS, EQ, POW). I distinctly remember the longest question asked to implement function to find largest common denominator between 2 numbers. All in all this test was very enjoyable - I was given 40 minutes to completed which proved to be more than enough as there was sufficient time for me to go over each answer again to verify I haven't made any silly mistakes. After the first test two of Ocado's engineers/developers took me on a tour of their test facility, which happened to be a large storage area located in the same building. It was very enjoyable to look at their experimental technology and how it is tested. Once the tour was finished, I sat down for a face-to-face interview with two FW/SW managers. Interview questions are specified below: