Applied online and got a called in June 2013. Could not attend the interview, but they called me again this year. I attend a group assessment. The first day was split in three parts: company presentation, 3 aptitude test and half of the people made 1:1 interview. The aptitude test were Abstract Reasoning, Mechanical Reasoning and Numerical Reasoning. I suggest to review all basic formula from math (volume, area, abbreviated formula, derivates, factorial numbers), physics (ohms law, speed, density, forces) and mechanics (springs, gears, equilibrium situation) plus all the conversion units. The second day started with personal presentation of each candidate ( be careful to express good the weakness that can affect your work), then two group exercises ( one with the importance of some objects when u are in the middle of the sea and the other one to build a paper bridge 1m heigh and 80cm large with 20 paper sheets and scotch), then the 1:1 interview with the rest of the candidates. During the interview, you have to assembly a valve in 5 minutes watching the technical draw.
The whole experience was really nice, the atmosphere was relaxed and I am really happy I attend it.
The results are coming in one month, so I still must wait for the answer ...