Greyorange

Role: Backend Developer

College: Not Specified

Interview Date: Not Specified

Interview Type: Not Specified

Result: Not Specified

Difficulty: Medium to Hard

Rounds: 5 rounds (2 coding, 3 interviews)

Topics Asked: Data Structures (Linked List, Stack, Hashing), Algorithms (Knapsack, DFS), Object-Oriented Programming (OOP), Design Patterns, Git, Docker, NoSQL, SQL, Cloud Computing (Docker containers), System Design.

Experience:

The interview process for a Backend Developer role at GreyOrange consisted of 5 rounds: 2 coding rounds and 3 interview rounds.

First Coding Round (HackerRank)

1. A matrix containing 0's and 1's. Set the whole row and column of a cell containing 0 to all 0's.
2. Convert a number 'm' to 'n' with minimum operations. The allowed operations were -1 and *2. For example: 4 and 6, the answer is 2 (4-1=3, 3*2=6).

Second Coding Round (HackerRank)

1. Given a matrix containing O's and X's. Convert all O's to X's which are fully surrounded by all X's. The approach involved handling boundary O's first and then using DFS for internal O's.
2. Direct knapsack problem.
3. Implement a circular linked list with dynamic insertion and deletion with minimum time complexity. Queries for insertion and deletion were given at runtime, and after 'n' operations, the linked list needed to be printed.

First Interview Round

1. Detect a cycle in a linked list and the point where the cycle begins.
2. Min stack implementation.
3. Modified previous question: find the middle element in this stack in minimum time complexity.
4. Questions asked in the coding test, asked some changes to optimize the algorithm.
5. Asked about hashing and linear probing.
6. Design patterns overview, and describe any two of them in detail.
7. Function overloading and overriding and the difference between them.

Second Interview Round

1. Virtual functions, Interfaces, polymorphism (both static and dynamic).
2. Design a system similar to GreyOrange where there is a central server monitoring all the robots.

Third Interview Round (Phone)

The interviewer asked about all the technologies the candidate had worked on. There was a discussion on GIT and NoSQL databases, specifically "Why not SQL?". Finally, a project was discussed.