The Trade Desk Senior Software Development Engineer interview questions

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. :)