Infosystems Java Developer Interview Questions and Answers

Round duration - 60 Minutes
Round difficulty - Easy

Q1. 
0/1 Knapsack Problem Statement
A thief is planning to rob a store and can carry a maximum weight of 'W' in his knapsack. The store contains 'N' items where the ith item has a weight of 'wi' and a value of...read more
Ans. 
Yes, the 0/1 Knapsack problem can be solved using dynamic programming with a space complexity of not more than O(W).
• Use a 1D array to store the maximum value that can be stolen for each weight capacity from 0 to W.

• Iterate through each item and update the array based on whether including the item would increase the total value.

• The final value in the array at index W will be the maximum value that can be stolen.
Answered by AI
Add your answer
Q2. 
Find the Second Largest Element
Given an array or list of integers 'ARR', identify the second largest element in 'ARR'.
If a second largest element does not exist, return -1.
Example:
Input:
ARR = [2,...read more
Ans. 
Find the second largest element in an array of integers.
• Iterate through the array to find the largest and second largest elements.

• Handle cases where all elements are identical.

• Return -1 if a second largest element does not exist.
Answered by AI
Add your answer

Round duration - 60 Minutes
Round difficulty - Easy

System Design Round

Q1. Design a system for Twitter, discussing its architecture, key components, and scalability considerations.
Ans. 
Design a scalable system for Twitter with key components and architecture.
• Use microservices architecture for scalability and fault isolation.

• Key components include user service, tweet service, timeline service, and notification service.

• Use a distributed database like Cassandra for storing tweets and user data.

• Implement a message queue like Kafka for handling real-time updates and notifications.

• Use a caching layer like ...read more
Answered by AI
Add your answer

Round duration - 30 Minutes
Round difficulty - Easy

It is just a formality

What is model binding

Q1. What is design pattern
Ans. 
Design pattern is a reusable solution to a commonly occurring problem in software design.
• Design patterns help in creating maintainable, scalable, and reusable code.

• They provide a common language for developers to communicate about solutions.

• Examples include Singleton, Factory, Observer, and Strategy patterns.
Answered by AI
Add your answer

I was asked with writing the code and algorithms. Also lots of MySQL queries

Q1. What is the interceptor
Ans. 
An interceptor is a software component that intercepts and modifies the behavior of a program or system.
• Interceptors are commonly used in software frameworks to add additional functionality to an application.

• They can be used to intercept and modify incoming or outgoing requests, such as adding authentication or logging.

• Interceptors can also be used to intercept method calls and perform actions before or after the metho...read more
Answered by AI
Add your answer

Q1. Laravel middleware Packages PHP OOPs MySql
Add your answer

Deeply concept of PHP working

Basic react, JS and CSS related questions were there.

Q1. Basic technical question on react, js and css
Add your answer

Q1. Only salary discussion was done.
Add your answer

Q1. First round was telephonic of 20 mins. They asked me about OOPS Concepts, Core java and collections. It was easy .
Add your answer
Q2. Throw and throws Diff Heap and stack Diff Arraylist and linkedlist Diff Why string is immutable in Java OOPS 4 pillars
Add your answer

Q1. This was 2nd Technical round(final round) . He asked me about my experience and technical skills. 1.Concurrenthashmap and hashtable 2.Internal working of concurrenthashmap 3.Comparable and Comparator Diff...read more
Add your answer