Summary
I interviewed for an SDE2 role at CoinSwitch, undergoing three rounds covering Data Structures & Algorithms, Low-Level Design, and High-Level Design. Despite a comprehensive interview, I was rejected due to lack of prior experience with their tech stack.
Full Experience
Education : Tier2 + Tier1
Work Ex : SDE2 at Indian E-commerce company(~3 yoe)
3 Rounds
Round1 : 2 DSA Questions
1. House Robber.
2. LCA.
Round2 : LLD
1. Had indepth discussion on current work for around 30mins.
2. LLD of a food delivery app.
Round3 : HLD + HM
1. Usual HM questions and stuff.
2. HLD of customer care chat section of any app, question related to product features , scalability etc etc.
Verdict : Rejected because of no prior experience with the tech stack.
Interview Questions (4)
A dynamic programming problem where the goal is to maximize the amount of money robbed from a row of houses, with the constraint that adjacent houses cannot be robbed.
Find the lowest common ancestor of two given nodes in a tree or a directed acyclic graph.
Design the low-level components and interactions for a food delivery application.
Design the high-level architecture for a customer care chat section within any application, including discussions on product features and scalability.
Summary
I had a negative interview experience at Coinswitch where I successfully passed the first DSA round by solving two LeetCode medium problems, but was then rejected without proper feedback.
Full Experience
I had a very unpleasant interview experience at Coinswitch. The first round was dedicated to Data Structures and Algorithms, where I was given two medium-level LeetCode questions. I managed to solve and run both problems successfully. Although further interviews were initially scheduled for the same day, I later received an email after the first round indicating that they were proceeding with other candidates. My subsequent attempts to obtain proper feedback were unfortunately met with silence, making it a truly frustrating experience.
Interview Questions (2)
There are a total of numCourses courses you have to take, labeled from 0 to numCourses - 1. You are given an array prerequisites where prerequisites[i] = [ai, bi] indicates that you must take course bi first if you want to take course ai. Return true if you can finish all courses. Otherwise, return false.
Summary
I applied for the SDE 1 role at CoinSwitch Kuber via LinkedIn and successfully cleared an online assessment followed by two interview rounds, ultimately receiving an offer.
Full Experience
I applied for the SDE 1 position at CoinSwitch Kuber after seeing a posting on LinkedIn. Shortly after applying, I received a link to complete a Hackerearth Online Assessment. This assessment included three medium-hard questions: one based on Dijkstra's Shortest Path Algorithm, another on Tree Traversal, and a third one that I couldn't recall. I managed to complete the first question and partially complete the second.
A few days later, a recruiter contacted me, informing me that there would only be two interview rounds: one focused on Data Structures & Algorithms (DSA) and one HR round.
My Round 1 (Problem Solving) lasted for 1 hour. We discussed two main problems:
- The first question involved a grid of
m*nsize, and I had to calculate the number of ways to move from the top-left corner to the bottom-right corner, only being allowed to move down and right. This was a straightforward Dynamic Programming problem. - The second problem presented a sorted array containing both negative and positive numbers. The task was to square all the numbers and return them in a sorted format. For example, given
[-5, -3, 0, 1, 4], the expected output was[0, 1, 9, 16, 25]. I first proposed a brute-force solution involving squaring all numbers and then sorting the array, which would have anO(n log n)complexity. The interviewer prompted me for a more optimized solution. I then suggested an approach where I stored negative and positive numbers in separate arrays, squared them individually, and then merged these two already sorted lists, achievingO(n)complexity. They pushed for even further optimization to use constant space, and while I was able to explain the approach using binary search and a two-pointer technique, there wasn't enough time to implement it. They seemed content with my approach.
Next was Round 2 (HR Round), which lasted for 30 minutes. This round primarily involved discussions about my current company and the projects I had worked on. I had to explain my projects in considerable detail. Additionally, I was asked to explain the database systems used by Google Sheets.
A few days following the interviews, I was extended an offer.
Interview Questions (3)
Given a grid of m*n size, calculate the number of ways to move from the top-left corner to the bottom-right corner if you can only move in down and right directions.
Given a sorted array of negative and positive numbers, square all of them and give the output in sorted format.
Example: input [-5, -3, 0, 1, 4], Expected output [0, 1, 9, 16, 25].
Explain the database systems used by Google Sheets.
Preparation Tips
My preparation involved rigorous practice of coding problems, particularly focusing on Data Structures & Algorithms. I brushed up on algorithms like Dijkstra's, tree traversals, dynamic programming, and various array manipulation techniques. I also prepared for discussions about my past projects and common HR-related questions, alongside system design concepts like database systems used in large-scale applications.