Given the root of a binary tree, return the length of the diameter of the tree.

"interview process is very lengthy took around 5 weeks, and expectations is very high in each round, for LLD working code is required, also dont mess your HM round since i felt like it contained more weightage"

"I interviewed for an AI Engineer internship, but the process was mostly DSA-heavy. I had an online coding round first, then a technical round with binary tree and DP questions, then another harder DSA round with DP and linked list questions, and finally an HR round. The online round covered arrays and strings, and the later rounds got progressively more difficult. The only non-DSA part was the last round, where they asked about my projects and previous experience. I didn't share the final outcome, but the main thing that stood out to me was how coding-focused the whole process was."

"- everyone was super nice - questions were like leet code but with a twist - time complexity always asked"

"The process was very nice, interviewed by people that would not be in my next team, but everybody was exceptionally nice. The questions in the ML system design round were not very deep and were more systems-oriented."

"Practice leetcode fundamentals (graph, tree), practice system design fundamentals, speaking/thinking out loud, being able to explain full flow of what happens from when user/request is received to processed to returned (ensure components are disconnected/missing a flow path)"