Eternal

Role: SDE-1

College: IIT

Interview Date: 2021

Interview Type: On-Campus, Full-Time

Result: Selected

Difficulty: Medium-Hard

Rounds: 1 Online Coding Round + 3 Interview Rounds

Topics Asked: Data Structures, Algorithms (Minimum operations to make row/column matrix equal, Next smallest palindrome, Totient function, Convert binary tree to doubly linked list, Anagram substring search, Maximum product subarray), Django project, SQL (basic joins), C++ STL map implementation, Computer Science Fundamentals (OS, Computer Networks, DSA, OOPs, DBMS).

Experience:

The Zomato interview process consisted of an online coding round and three virtual interview rounds.

Online Coding Round:
Conducted on Intervue, this round had 4 questions to be solved in 90 minutes. Three of the problems were: "Minimum operations required to make row/column matrix equal" (GeeksforGeeks), "Next smallest palindrome" (InterviewBit), and a problem related to the Totient function (HackerEarth). The candidate solved 3 problems completely, and those who solved 2.5 were also shortlisted. Out of approximately 500 candidates, 164 were shortlisted for the online test, and then 18 for final interview rounds.

Round 1: Technical Interview
The interviewer and candidate introduced themselves. The interviewer then delved into the candidate's Django project, asking about various functionalities of templates. A SQL query based on basic joins was asked, as MySQL was mentioned on the resume. Next, the candidate was given a problem to convert a binary tree to a doubly linked list using inorder traversal. The recursive approach was explained and coded. Another problem involved anagram substring search, where the candidate first presented a brute-force approach, coded it, and then optimized it using a sliding window and hashmaps. Questions about C++ STL map implementation were also asked. Finally, a problem on maximum product subarray was given, for which the candidate provided a DP solution and explained its intuition with test cases, including zeros and negative numbers, before coding it.

Round 2: Advanced Technical Interview
This round had two interviewers and focused on practical implementation and system design. The interviewer briefly reviewed all projects. Backend implementation logic in Golang was a task, focusing on optimizing with goroutines and channels. System design involved designing a real-time data streaming and processing pipeline, including choosing appropriate technologies and handling scalability. The candidate also demonstrated continuous learning through personal projects and consistent practice.

Round 3: HR Round
This round was largely a formality. The HR and another senior developer provided insights into Zomato's working culture. The candidate was informed of their selection immediately after Round 2.