Meta | Onsite | Software Engineer E4 | USA | Offer
Question Details
I had the onsite full loop of interviews on the same day: -
Behavioral 2
coding System design ## Behavioral I had a document from 3 years ago for an interview of that...
Full Details
I had the onsite full loop of interviews on the same day:
Behavioral 2
coding System design
Behavioral
I had a document from 3 years ago for an interview of that time, I just quickly updated it with newer stories. I don\'t remember the questions, they were the usual "Tell me about a time you received feedback" etc
Coding 1
There was a change: implement a class that receives k sorted lists (array lists, not linked lists) in the constructor, with a method next() that returns the next smallest number of all the lists.
I proposed heap solution, I took a good time writing the code, had a few bugs and corrected them.
Got lucky because it was the last problem I solved when studying the day before lol. However I didn\'t implement the doubly linked list solution.
I asked when the recency should be updated, interviewer said on both get() and put(). I said that if it was only on put() I would just use a deque, but started thinking out loud about another data structure that would allow make it the get() method run in O(1). I suggested a simple linked list, discussed with interviewer and then started writing code. I didn\'t finish due to time.
I think he liked the question I asked him
Coding 2
Interviewer got really interested about something from my resume, spent the first 10 minutes of the interview talking about it. Got along really well lol
I proposed heap solution, he knew I knew about quickselect and said it\'s impossible to write it on time so I started with the heap and finished it.
I proposed storing indices of non-zero elements, went ahead and coded it. No follow up from LeetCode.
We talked more after the problems, he liked my questions as well
System design
- Design Instagram
When identifying the requirements the interviewer simplified the problem to only posting and following. This was a fullstack interview but I was focusing more on the backend. He asked a lot of things that I was missing as I was talking out loud, but I managed to follow up correctly I guess
Conclusions
Luckily I had already solved the 4 problems I got when preparing for the Screening interview. I could definitely had done better on the system design, but I guess it was good enough
I got no feedback, just a confirmation that an offer is coming
Keep practicing tagged problems and you got this!
About This Question
This is a reported interview question from a meta interview for a backend role (mid level) during the system design round reported in 2025.
It covers the following topics: Arrays, Linked List, System Design, Queue, Behavioral, Heap, Stack .
Difficulty rating: Easy