Received an email from the CEO two days after I submitted my online application which was made to seem personalised (but was automated) asking me to complete an assignment within 7 days. Excited at the quick response I completed the assignment straight away and devoted a fair amount of time to it. After submission I was told I'd hear back within a few days (but again it was an automated email). It then took them 6 weeks to get back to me and tell me they received hundreds of applications and I was unsuccessful.
Essentially it seems they asked every single applicant to complete an assignment, probably before even reading the online application, which is my opinion is not very ethical and a bit unfair. Be careful if they ask you to do an assignment and be aware of the amount of applications they are receiving.