Applied online - got really interested in the company after doing a research on it. Got contacted by a recruiter, was offered an online coding test. Got an email with link to HackerRank, the test was to sort characters in a string. Provided a one-liner solution (C# + Linq), passed all tests inside HackerRank system. Notified recruiter, never heard back. Decided to follow up some time later - got a response which looked very generic, like the team took an extensive effort to analyze all aspects of my solution and found that it didn't meed their requirements. :)

Met with TTD at HackerX, then followed up with a 1:1 interview in person at their Sydney office. This interview was more general aptitude/team fit. This was followed by a take home coding exercise that I was to complete(no time limit given) and submit. My submission was reviewed and some rework suggestions that I was asked to implement. After this I had 5 round of intensive technical interviews, each interview between 1-2hrs in duration. These were conducted over online meetings since most of the tech leadership is in the US.