Google R1 two-round interview experience
Summary
I completed Google R1 interview consisting of coding and behavioral questions, solved two coding problems (Top K Frequent Elements and Longest Consecutive Path in a Binary Tree), and received a pass notification on 12/19.
Full Experience
The overall process started with submitting the resume, followed by receiving the OA, and then moving to the next step, which included submitting additional materials and scheduling interviews. In terms of timeline, the application was submitted on 10/02, the OA was received on 11/26, and the Next Step notification came on 12/02, together with a request to submit the transcript. After that, there was the R1 interview. R1 was completed on 12/12, and the pass notification was received on 12/19.
R1: Coding + BQ
R1 included both coding and behavioral questions. For the coding part, because the first question was solved relatively quickly, there was enough time to work on a second question.
The first question was Top K Frequent Elements. Given a non-empty integer array, return the k elements with the highest frequency. One solution is to use a HashMap to count frequencies and then maintain a min-heap of size k. Another solution is to use bucket sort. The interviewer followed up by asking whether the time complexity could be better than O(N log N), and how the space complexity could be optimized.
The second question was the Longest Consecutive Path in a Binary Tree. The path must go from parent to child, and the node values must be continuously increasing. The solution is to use DFS, maintaining the current consecutive length and a global maximum value. The follow-up question was how to modify the solution if the path could go in any direction.
BQ Round
The behavioral questions mainly focused on project experience and common behavioral topics. The questions included: describe a time when you handled a difficult customer or stakeholder; describe a time when you simplified a complex process or system; describe a time when you made a mistake and how you fixed it; describe a time when you had to quickly learn a new technology to complete a task; describe a time when you disagreed with a manager’s decision; and describe a time when you went above and beyond for a customer.
Overall, this round focused more on communication, judgment, and reflection based on real project experience.
R2: Onsite
R2 was an onsite interview. According to the timeline, the onsite took place in NYC on 02/06. The article did not provide detailed questions for each round. It only mentioned that Google onsite interviews usually cover coding, behavioral questions, and culture fit. They may also include system design, machine learning design, and behavioral rounds.
More Google interview experience can be found here https://interview-aid.com/en/vo/google-r1-bq-code/
Interview Questions (2)
Top K Frequent Elements
Given a non-empty integer array, return the k elements with the highest frequency. One solution is to use a HashMap to count frequencies and then maintain a min‑heap of size k. Another solution is to use bucket sort. The interviewer asked whether the time complexity could be better than O(N log N) and how the space complexity could be optimized.
Longest Consecutive Path in a Binary Tree
Find the longest path in a binary tree where the path must go from parent to child and node values are continuously increasing. The solution uses DFS, maintaining the current consecutive length and a global maximum. A follow‑up asks how to modify the solution if the path could go in any direction.