Physicswallah Backend Developer Interview Questions, Process, and Tips

Find the longest substring without repeating characters in a given string.

• Use a sliding window approach to track the longest substring without repeating characters.

• Keep track of the characters seen so far using a hashmap.

• Update the start index of the window when a repeating character is encountered.

A social media app allows users to connect, share content, and interact with each other.

• User profiles with personal information and photos

• News feed displaying posts from friends and followed accounts

• Messaging feature for private communication

• Ability to like, comment, and share posts

• Notification system for updates and interactions

The four pillars of Software Development are requirements, design, implementation, and testing.

• Requirements: Gathering and analyzing the needs of the software.

• Design: Creating a blueprint or plan for the software.

• Implementation: Writing the actual code based on the design.

• Testing: Checking the software for bugs and ensuring it meets requirements.

ACID properties are a set of properties that guarantee reliable and consistent transactions in a database system.

• Atomicity: All operations in a transaction are completed successfully or none at all.

• Consistency: Data is always in a valid state before and after a transaction.

• Isolation: Transactions are isolated from each other until they are completed.

• Durability: Once a transaction is committed, its changes are permanent