OA plus 2 interview rounds covering probability, DSA, system design, and OS

Application

I applied through university. The process took 2 days. I interviewed at Zomato in Jul 2025

Interview

Online Assessment followed by 2 rounds of interview. Cleared OA and gave round 1. Did not make it to 2nd round. Questions based on probability, DSA, System design, Operating Systems asked in round 1.

Interview questions [1]

Question 1

Design a system which takes in orders along with their timestamp. Write a function to retrive the number of orders in the last 30 minutes. Preferably in O(1).