Concentric AI | Software Engineer Interview | Pune
Question Details
Concentric AI Pune had total 4 Technical Rounds. 2 Rounds online + 2 rounds offline 1st Round (30 mins): https://leetcode.com/problems/daily-temperatures/description/ Post solving this problem, interviewer asked to implement my custom stack and use my...
Full Details
Concentric AI Pune had total 4 Technical Rounds.
2 Rounds online + 2 rounds offline
1st Round (30 mins):
https://leetcode.com/problems/daily-temperatures/description/
Post solving this problem, interviewer asked to implement my custom stack and use my custom stack in colving above problem.
I did all in 30 mins
2nd Round (60 mins)
https://leetcode.com/problems/merge-two-sorted-lists/
I solve above question in 20-25 mins
Post that he increased the difficulty and asked to merge K LinkedList :
https://leetcode.com/problems/merge-k-sorted-lists/
I tried to solve it with proper approach but couldn\'t get idea about Heap but overall my solution worked.
3rd Round (60 mins) (offline):
Problem statement given on white board:
Given a messages receievd from Queue/Kafka attached with timestamp, discard messages post 60 secs if duplicate found.
I solved it using Queue and HashMap.
It was open ended question and interviewer was helping enough to reach the answer.
Post the question, asked few questions on Kafka/Elastic/ tech basically you have worked upon.
Interveiw 4 (60 mins) (offline)
System design Backup System.
This too open ended question so ask questions on requirements and draw the High Level design of the System which you would like to build to create Backup System/Service.
PS: I am about to receive the offer. will update details post receiving the offer.
About This Question
This is a reported interview question from a elastic interview for a data eng role during the system design round reported in 2025.
It covers the following topics: Hash Table, Heap, Linked List, Queue, Stack, System Design .
Topics
About Elastic Interview Reports
This question was reported by a candidate who interviewed at Elastic. LeakCode aggregates interview reports from 10+ sources, including 1Point3Acres, Glassdoor, LeetCode Discuss, Blind, Reddit, Indeed, and Nowcoder. Each report is translated where necessary, deduplicated against existing entries, and tagged by company, role, round type, and reporting date.
Use this question as one calibration data point, not a memorization target. Companies typically rotate their question pools every 2-4 months; the exact wording of a 2024 question may differ from what you encounter today. The underlying pattern, difficulty level, and follow-up depth at Elastic are the higher-signal extractions to take from this report.
For broader preparation context, the Elastic interview process typically includes a recruiter screen, one or two technical phone screens, and a 4-5 round on-site loop covering coding, system design (at L4+ levels), and behavioral. Reports tagged on LeakCode show the round-by-round distribution and typical difficulty calibration. To browse questions filtered by round type and seniority, use the company hub linked above.
How To Practice This Type of Question
Solve similar problems on LeetCode under timed conditions (25-35 minutes per medium difficulty). The goal is pattern recognition: recognize the underlying technique (sliding window, two-pointer, BFS, memoized recursion, etc.) within 60-90 seconds of reading. Strong candidates verbalize their hypothesis out loud before coding, then iterate based on feedback. Weak candidates dive into implementation immediately, lose time on the wrong approach, and run out of time for follow-ups.
Companies update their question pools every 2-4 months. The exact wording of any given question may have been retired by the time you interview. Focus your prep on the pattern, not the specific problem. The patterns that appear in Elastic reports consistently are the ones worth investing in; one-off niche problems are not.
During Your Elastic Round
Apply the standard interview round template: clarify requirements (2-3 minutes), state your approach out loud and confirm direction with the interviewer (3-5 minutes), code with narration (15-25 minutes), test with concrete examples including edge cases (5 minutes), discuss optimization or trade-offs if time permits (5 minutes). This template is universally accepted across FAANG and adjacent companies; deviating from it produces weaker interviewer feedback signal.
The single most predictive failure mode in Elastic reports tagged "no hire": not asking clarifying questions. Interviewers are explicitly trained to weight this. Strong candidates ask 3-5 clarifying questions even on problems that look obvious; weak candidates dive into code immediately. The clarifying-question check is often the first signal recorded in the interviewer's written notes.