Confluent | Senior Software Engineer | Rejected
Summary
I interviewed for a Senior Software Engineer position at Confluent through a referral, going through a qualifier round, and two coding rounds. I unfortunately got ghosted after the second round.
Full 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 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.
Interview Questions (3)
Football Club Revenue Analysis (API & Pricing)
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
Implement Unix 'tail -n' Command
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.
Subset Sum for Bank Transactions
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.