Number of rounds – 3

Round 1 – Online Assessment

P1 – Special Array

• An array has aa special Integer if that integer can be formed by calculating the sum of a number and its reverse Eg) Input : [22,121] Output : 2 Explanation : 22 -> 11 + 11 , 121 -> 29 + 92

P2 - Don't exactly remember

Round 2 – DSA and Algo

P1 - Balanced Parenthesis check

• https://leetcode.com/problems/valid-parentheses/

P2 - Given a Tree, Print the following pattern

Pattern : 8 10 14 3 6 7 13 1 4

P3 - Basic Java Questions

• Can constructor be made final in java
• Can Objects be created from abstract class. Can abstract class have constructors
• Comparable vs Comparator

Round 3 – Java, Spring and HLD

• Binfunctions in Java 8
• Create custom compile time and runtime exception
• Capturing order of exceptions in catch clause
• Spring MVC pattern
• Cowin - HLD design

Cowin - HLD Design

• Different Tables to be used

• Registering a User

• Functionality to search based on Area Pincode, vaccine type

• Handling Single User registering for multiple people

• Type of Database to be used, and Database sharding strategies

• Handling concurrency and parellelism when multiple users book for a time slot having limited number of vaccines. Eg) within 2 - 2:30 pm slot having 20 available vaccines how to handle multiple users booking that slot

• After a slot is booked, how to verify if that particular person registered for that slot has been vaccinated or not for that particular slot