The process was fine at the assessment centre they are very informal but they are really selling the move to Argentina. However, they do not offer any sort of feedback even when you've reached the final stage before the offer.
I applied online. I interviewed at Brainlabs (London, England) in Jun 2017
Interview
The interview process involved a very simple online application that just consisted of uploading a CV. They got back to me quickly and I was given the opportunity to select a first-round interview slot. The first round of interviews involved a short presentation (I didn't use a powerpoint or visual aids but the other two candidates did) the presentations were varied and informal. There was then a series of tests on a computer. One maths one which I didn't feel that I did well in and included a lot of geometry, an easy verbal reasoning one and two tests on the company, so read the handbook and remember which clients they work with. It's also worth really working out what brainlabs do, and some stuff about digital marketing generally. The interview afterwards was short and informal.
I was invited for a second round which started with an excel task. No knowledge of excel needed but just an understanding of how the business works and strategies for managing successful PPC campaigns. This was definitely what let me down! Afterwards there were 3 10-minute interviews where the questions were very standard. I didn't get an offer.