I applied online. The process took 4 weeks. I interviewed at Metaswitch (Enfield, England) in Oct 2014
Interview
Applied online, quite few pages to fill in with. Asked to have a one day first round interview. Three very tight aptitude test, 50 alphabetical, 40 picture logical, 30 maths questions. Then three written questions, one Greek, one follow code, one Black Jack kind. After lunch, interviews with the written answer and general questions.