Confluent Senior Software Engineer Interview Experience and Rejection
Interview Experience
Got interview through referral. ## Qualifier Round: Analyze potential revenue for football (soccer) clubs based on their stadium capacity and historical performance. Use HTTP GET requests to access a
Full Details
Got interview through referral. ## Qualifier Round: Analyze potential revenue for football (soccer) clubs based on their stadium capacity and historical performance. Use HTTP GET requests to access a football club database via the URL: ---a mock endpoint was provided----/football_teams?league={league_name} with pagination available via &page={num}. Replace {league_name} and {num}. The API response includes: page: current page number per_page: maximum results per page total: total number of records total_pages: total number of pages data: array of club information Each entry in the data array contains: name: club name league: league name stadium_capacity: stadium capacity number_of_champions_league_won: Champions League titles total_silverware_count: total trophies won league_top_three_finishes: number of top-three finishes other details not relevant to this question Ticket Pricing Rules Calculate ticket pricing based on total_silverware_count: > 40 → 1.5 USD per ticket > 25 → 1.25 USD per ticket > 10 → 1 USD per ticket <= 10 → 0.5 USD per ticket Task Determine: Total earnings for a league Average earnings per match Notes: A season: each team plays every other team twice (home and away) Average = total earnings / total matches Round both values down to nearest integer ## Coding 1 Implement unix 'tail -n' command to print last n lines of a file. Concurrency handling was not required. There were follow ups related to memory and time complexity optimization. Running optimal code was required. gave a rolling window solution and gave working code for it. ## Coding 2 Given a list of numbers, each representing a bank account transaction (positive for credit and negative for debit) your task it to tell if there exists a sequence of transactions which can lead to a given balance amount. Started with O(n^n) brute force solution then identified subset sum and gave a O(2^n) solution. Interviwer wanted to know till what what n can this work, I was eyeballing it and gave a loose bound (50) but a concrete answer was needed like n upto 25 with reasoning why 25 would work and 26 won't, had to do some calculations and wasted like 30 mins till here. After this interviewer asked to code the second approach. Could not get to discussing optimal approach. Running optimal code was required, interviewer ran a few edge cases. In my case edge cases were handled but the approach wasn't optimal. Got ghosted after 2nd round.
About This Question
This is a candidate experience report from a confluent interview for a swe role (senior level) reported in 2026.
It covers the following topics: Arrays, Os, Sql, System Design .
Topics
About Confluent Interview Reports
This question was reported by a candidate who interviewed at Confluent. 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 Confluent are the higher-signal extractions to take from this report.
For broader preparation context, the Confluent 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 Confluent reports consistently are the ones worth investing in; one-off niche problems are not.
During Your Confluent 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 Confluent 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.