1st Technical round was about creating a Tree based data structure, each round with more and more increasing difficulty about some requirements provided by the interviewer. 1st phone round was about prev experiences and technical question regarding my background, pretty deep.
I applied through a recruiter. I interviewed at Topaz Labs (Dallas, TX) in Jun 2025
Interview
Problem:
Given an array of integers, return the length of the longest increasing subsequence.
Follow-ups:
Optimize to O(n log n).
Handle negative numbers.
Return actual subsequence.
Another question: find unique strings given anagrams
I applied online. The process took 2 weeks. I interviewed at Topaz Labs in Mar 2025
Interview
There were 4 round in total. I failed at third round. The phone interview with HR and the first round of technical interview were great. They are responsive and helpful. However, the second round technical interview with engineering lead was not joyful. The interviewer didn't open his camera and not focus on the interview at all. It should be the basic things for the interview. Besides, I expected much more interaction with the interviewer when we were discussing the system design question but the interviewer was quiet. It seems like he was working on something else during the interview.
Interview questions [1]
Question 1
1. 2 medium leetcode problem.
2. system design for async time consuming process