TikTok Backend Engineer interview questions

Received online assessment, contained 2 MCQ and 3 Leetcode-style questions. MCQs were doable (network-related) but technical questions were medium-hard. Questions were simple on the surface but required a different technique that you wouldn't think of at first glance.

Applied to TikTok USDS. Got a hard-level leetcode question despite the expectations set by the recruiter in an email: "The technical interviews will be done on HackerRank with an Engineer. It will be an easy/medium leetcode style problem that may include data structures and algorithms and questions about your technical experience."