Three phases. Initial meeting with the Chief Scientific Officer, followed up by a good programming assignment (a fair length), finally a group interview with the relevant development team and the CSO - this included a review of my code. The CSO and team all seemed absolutely wonderful and it was only down to inability to suitably relocate to the Cambridge area (due to my wife's work) that I needed to decline. This company had a brilliant smaller team feel who I strongly believe would have supported by career really well. A very positive experience.