I applied online. The process took 6 weeks.

Applied on Sept. 2nd. They responded on Sept. 4th. Then 3 interviews occurred; the filter interview, interview with new boss / head of department, and interactive technical interview on Sept. 10th. Then things got very strange. Radio silence until Sept. 16th when I contacted them to ask what's up? The recruiter asked to call me but missed the call easily 4 or 5 times causing delays until Sept. 24th when we finally spoke.

The recruiter finally said that they want to move forward but due to summer vacations they want to delay for about another 2 weeks. I contacted again on Oct. 7th at which time the recruiter did another round of miss the call yet again on Oct. 8th. So next call is scheduled for Oct. 9th. At this stage I'm thinking that if they do make an offer then I'll decline because it's just too strange. As a candidate I feel like they initially moved fast but then put me on the back burner... 3 interviews within the first week but then various delays and unprofessional behaviour for the next 5 weeks, with no explanation and very repeated weird behaviour from the recruiter.

Relatively simple scripting exercise using CodeSignal where knowledge of binary search is necessary to solve the question efficiently.

It didn't seem particularly relevant to the job.

I guess it's more about how you approach the given problem?

So they want to know if you avoid slower solutions and at least know and are confident implementing binary search?!