I had a Skype interview with a recruiter of the company that lasted 45 minutes and was mostly behavioural questions. After 3 weeks I was invited to an assessment centre at East Horsley, Surrey that lasted 2 days. The first day included a presentation of the company, a group exercise and an analysis exercise. The second day had an interview, a presentation and a role play. All in all, the company is interested in people that are ready to sell and are really motivated with the products! If you cannot demonstrate this, probably you will not make it!