GridRay interview experience Real time questions & tips from candidates to crack your interview

Fullstack Developer

GridRay

1 rounds | 2 Coding problems

Anonymous

Fresher | Feb 2025

Rejected

Interview preparation journey

Journey

My journey toward securing a Full-Stack Developer role at Gridray has been both enriching and inspiring. It began with building a strong foundation in data structures and algorithms (DSA). I firmly believe that mastering these fundamental concepts is key to solving real-world problems, which is why I dedicated significant time to honing them. During my preparation, I focused on understanding various data structures and their practical applications. This knowledge not only helped me tackle complex coding problems but also gave me the confidence to approach challenges logically and systematically. Another crucial part of my preparation was developing strong problem-solving skills through consistent practice. Alongside DSA, I emphasized full-stack development — including backend technologies such as databases, APIs, and server-side programming, as well as frontend frameworks like React.js, HTML, CSS, and JavaScript. I also explored system design, scalability, and performance optimization to strengthen my overall skill set. I discovered the opportunity at Gridray on Indeed, applied, and was shortlisted for the interview. The selection process involved two rounds, and my dedication to understanding both backend and frontend principles played a pivotal role in my success. This experience has been instrumental in shaping my technical journey and preparing me for future opportunities in full-stack development.

Application story

I applied for the position through a referral on LinkedIn and Indeed, which led to the interview process. During the interview, I had the opportunity to showcase my skills and discuss my previous work. The entire journey was a valuable learning experience, helping me gain a deeper understanding of the role and identify areas for improvement in my preparation.

Why selected/rejected for the role?

I believe I was not selected for this role because they were looking for a candidate with more advanced backend development skills, particularly someone with a more comprehensive portfolio demonstrating hands-on experience with real-world projects. While I had a solid understanding of the required concepts, a stronger demonstration of my practical expertise and specialized backend work could have better aligned with their expectations. This experience highlighted the importance of tailoring my preparation and portfolio to match the specific technical requirements and scope of the position.

Preparation

Duration: 1 month

Topics: Arrays, Strings, Sliding Window, OOPs, Trees, Linked List, HashMaps, Node.js, JavaScript, Python (Flask, Django), React.js

Tip

Tip 1: Understand the problem logic, not just the solutions (arrays, strings, sliding window).

Tip 2: Practice trees, linked lists, and hashmaps by coding them from scratch.

Tip 3: Build projects using Node.js, JavaScript, and Flask for hands-on backend experience.

Application process

Where: Linkedin

Eligibility: No criteria, (Salary Package - 8 LPA)

Resume tip

Tip 1: Know your projects thoroughly and be honest about them.

Tip 2: Include relevant projects that effectively showcase your skills and experience.

Interview rounds

Round

Easy

Video Call

Duration60 minutes

Interview date8 Feb 2025

Coding problem2

1. Max Substring Occurrences

Moderate

0/80

Asked in company

You are given an array of strings, arr, containing N strings, and a non-empty target substring, target. Your task is to find and return the string from the array that contains the highest number of occurrences of the target substring.

There are two important rules to consider:

1) Overlapping Occurrences: The occurrences of target within a string are allowed to overlap. For example, if target is "aba", the string "ababa" contains two occurrences of the target: one starting at index 0 and another starting at index 2.

2) Tie-breaking: If two or more strings have the same maximum number of occurrences, you must return the one that appears first in the input array.

Problem approach

Step 1: I analyzed the problem and realized that I needed to count overlapping occurrences of a given substring within each string in an array. Traditional methods that count only non-overlapping occurrences wouldn’t capture all instances.

Step 2: I decided to implement a sliding window approach, where the window size was fixed to the length of the target substring. I slid this window one character at a time over each string, checking if the windowed portion matched the target substring.

Step 3: I wrote a helper function to perform the sliding window count. In this function, I iterated from the start of the string to the point where a complete window could be formed. For each position, I extracted a substring of the window size and compared it with the target, incrementing a counter upon a match.

Step 4: I applied the sliding window count function to each string in the given array. As I processed each string, I kept track of the number of target substring occurrences.

Step 5: I compared the counts across all strings and selected the string that had the highest count. This string represented the final answer to the problem.

Step 6: Finally, I tested the solution with various examples (including cases with overlapping occurrences) to ensure that the sliding window approach correctly captured every instance of the target substring.

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