My experience regarding recent SSE interview rounds with Confluent -
I took a referral.
After 20 days, recruiter called me and asked to schedule a Qualifer round.
Qualifier Round:
I was asked a DSA+LLD question and was supposed to implement and run it on coderpad. There were followup question on time complexity and Concurrency(Locking especially).
Recruiter mailed after 3 days after followup and scheduled full onsite loop.
Onsite 1
Was asked a DSA question in 2 parts first being easy-medium and second being medium-hard. Again working code was required with good coding practice. Wrote it nicely and interviewer was impressed.
Onsite 2
Was Asked a LLD question particularly on optimizing memory while reading a huge file as part of the problem. Awareness of low level language memory constucts was key. Was able to solve it and run. Working code was important again. Discussed further optimization on memory access when asked but could not code as we were out of time. Struggled a little with API knowledge but was able to get through. Interviewer seemed fine in the end.
Onsite 3
Was Asked a HLD question and was the easist round as HLD being my favourite and forte. Had to draw and explain the thought process with tradeoffs being made. Interviewer seemed happy.
Onsite 4
This was a deep dive+cultural fit round. Usual question around the project and different phases and situations in project and how did i handle them. This went really well.
After one week, followed up with recruiter and they said its a hire call. They setup a role sell call post that.
All the interviewer were very nice and jolly. Everything happened as scheduled on time. It was a very nice experience.
Offer - https://leetcode.com/discuss/compensation/5161790/Confluent-or-Senior-Software-Engineer-or-Remote
Questions - https://leetcode.com/discuss/interview-experience/5047273/Confluent-Onsite-Interview-Experience-Rejected
Looks like OP of questions post and i got interviewed during exact same time xD
Note:- There are always followups on the question in terms of approach, testing, tradeoffs as the questions are quite open ended in terms of expectations.