Summary
I recently interviewed for the Software Engineer role at ZL Tech and successfully cleared all technical rounds, leading to a final selection among 7 candidates.
Full Experience
I recently went through the hiring process at ZL Tech for the Software Engineer role. The selection process involved four rounds. The first was an Aptitude Test consisting of 50 questions in 16 minutes, where speed and accuracy were paramount; only 39 candidates qualified this round. The second round was an Online Technical Test with standard DSA-based MCQs and coding problems, assessing my problem-solving approach and correctness.
I then proceeded to two Technical Interview rounds. Round 1 was heavily DSA-focused, where I discussed and wrote code for problems like Lowest Common Ancestor in BST, Merge Sort, Rotten Oranges (a minimum time problem), and finding the Median in a data stream. Technical Interview – Round 2 involved questions on dynamic programming like calculating the number of ways to reach the end of a grid (only moving right or down), searching in a rotated sorted array, and conceptual questions on OOP and DBMS. We also had discussions around my internships and projects.
The interviewers were friendly and supportive throughout the process. Their primary focus was on my clear thinking, problem-solving approach, and understanding of time/space complexity. I was among the 7 candidates who were finally selected out of 17 shortlisted for interviews.
Interview Questions (7)
Find the lowest common ancestor (LCA) of two given nodes in a Binary Search Tree (BST).
Implement the Merge Sort algorithm for sorting an array or list of elements.
Given a grid of oranges (0: empty, 1: fresh, 2: rotten). Every minute, any fresh orange adjacent (4-directionally) to a rotten orange becomes rotten. Determine the minimum time required for all fresh oranges to rot. If impossible, return -1.
Design a data structure that supports adding new numbers and efficiently finding the median of all numbers added so far. I had to discuss the approach and write code for it.
Given an m x n grid, find the number of unique paths to reach the bottom-right corner from the top-left corner, only being able to move right or down.
Search for a target value in a sorted array that has been rotated at an unknown pivot point. The array was originally sorted in ascending order.
Conceptual questions covering Object-Oriented Programming (OOP) principles and Database Management Systems (DBMS).