The initial contact came from a headhunter. After that a 1 hour Hackerrank (HR) test followed to determine the technical ability. These days a solutions architect at TTD is more of a traveling solutions engineer than just a technical account manager. Decent coding experience is expected and as essential for the job as consulting experience. The problem was comparable to one of medium difficulty at Hackerrank and had some sneaky time / memory constraints to enforce only a well designed algorithm would pass. After successfully solving that, 3 video interviews followed with the internal recruiter, the (US based) hiring manager and the GM of product. Then came a 4 hour personal interview round in the office I was applying for. The panel consisted of the local lead engineer, director of engineering, director of partnerships and GM of business development. Each of them took 45mins to an hour to interview me 1:1. This way the key role aspects (technical as well as commercial) were well covered. It also allowed a good insight into the teams a candidate getting the offer would need to collaborate with and their leadership. I had the feeling the company valued me as candidate. Everyone I spoke to was well prepared and had a good understanding of my CV. They also answered all of my questions and came across as people I'd like working with. The overall process took about 6 weeks, which I expected because of the role offered and the holidays involved in between. I'd recommend applying there based on my experience.