Goibibo Interview Experience

The interview process in all consisted of 3 rounds, I was applying for Software Developer. Every round started about yourself, experience with projects etc. Round 1:  It was mainly to test your problem solving skills, knowledge of data structures etc. It started with 2 puzzles mainly

1. Given a triangle and 3 ants are sitting at the corner of each triangle, each ant can move in any direction along the edge of triangle, you need to find the probability of any two of them meeting.
2. Given 2 hours glasses of 7hrs and 4 hrs, you need to measure 9 hrs.

Then there was some data structures discussion about linkedList, trees, hashMaps, collision in hashMaps etc. After that there were few of coding questions like:

1. There is an unsorted array of positive numbers, every number has exactly one duplicate except one number. find the one number which doesn't have a duplicate without using any extra space. (Hint: XOR)
2. Merge K Sorted Arrays
3. Implement Stack using a singly linkedList (O(1) for insertion and deletion).
4. Implement Merge Sort

Round 2: This round was mainly based on LLD, database questions and some behavioral questions. Some of the questions are as follows:

1. Implement Calendar with support of multiple timezones in multiple locations. Print Notification 10 minutes before each event, with automatic selection of timezones.
2. Design a Crawling engine which has a N concurrency with maximum Api hit of  M rate per minute on a specific site.
3. Two MySql questions involving inner join, group by, count, and order by.
4. Discussion on micro-service architecture, how rest api work.

Round 3: This round was mainly to test OS knowledge involving concepts like pthreads, Threads vs Process, Paging, Caching, Encodings, Unicode, Physical Memory vs Virtual Memory etc. with some discussion on past projects too. One Coding questions was given to find number of days between 2 dates.