The first step of the application involved answering a number of questions and submitting them online. I found the HR staff to be very helpful and I was even emailed half way through my application to see if I needed assistance in finishing (it's possible to save the application and return to it at a later date).
The second stage involved an online aptitude test which was actually quite enjoyable and lasts about 25 mins.
I was then invited to an assessment centre at the London office and asked to prepare a 10 minute presentation. Other activities on the day involved an attention to detail exercise, an email writing exercise (I think the trick here was to be very concise and include only necessary information), a one hour face to face interview, a group exercise, a technical test, and a presentation to three senior engineers and other graduates.
The atmosphere on the day was very relaxed and all members of staff were very friendly and informative. At the end of the day it's about graduates getting to know Cundall as much as it was them getting to know graduates. I did better in some exercises than others do don't stress on the day if you don't ace everything!
I received an offer about 10 days after the assessment centre.