Design Rounds
Questions:
- Design a simple version of Instagram.
- Live Comment Updates with a focus on how this works globally.
- Design an Uber-like system with a focus on global scale.
Candidate's Approach
- Prepared using HelloInterview and supplemented with personal research, notes, and videos.
- Practiced writing requirements, entities, and APIs in under 10 minutes.
- Focused on control and data flow, and specifics of the design elements.
Interviewer's Feedback
- According to the recruiter, the candidate performed well in these rounds.
Coding Rounds
Questions:
- LCA using the parent pointer (Leetcode: 1650)
- Range Sum of a BST (Leetcode: 938)
- Sub Array == K (only positive numbers 1-n) (Leetcode: 560)
- Merge 3 Sorted Lists without duplicates (Leetcode: 23)
Candidate's Approach
- For LCA, initially wrote a hash solution but was guided towards a two-pointer solution, which had a bug.
- For Range Sum of a BST, missed the BST property initially and struggled with conditions.
- For Sub Array == K, discussed O(1) solutions but was biased towards a sliding window technique.
- For Merge 3 Sorted Lists, lost clarity and wrote suboptimal code with syntax errors.
Interviewer's Feedback
- The candidate struggled with clarity and optimal solutions, particularly in memory usage.
- Noted that the interviewers were consistent in their questioning, aligning with the Leetcode top 100+ questions.