The process took all-in-all around 5 months from initial contact to final acceptance. I was asked to travel to the London office upon completion of a coding task, where I undertook a series of activities; consisting of a 10min presentation (subject of interest), front-end dev interview, wonderlic test, logic test and a social and economic justice interview. All the people I came into contact with were extremely friendly and supportive, and quite obviously knew their stuff. After passing this stage, I was invited to do yet another coding task - this time back end. Upon review of the application, I was invited to Manchester where I completed a back-end developer interview. Once approved, the final stage was an interview with a manager before an offer was extended.
If looking to apply, be passionate about changing people's lives through the use of technology. If you don't - they will catch you out. It's not the easiest process to go through, but certainly an enjoyable experience. Be yourself.