Interview Questions and Answers

Sort array of strings based on frequency of digits in each element.

• Create a dictionary to store frequency of digits in each element.

• Sort the array based on the frequency of digits using the dictionary.

• Handle ties by sorting based on the original order of elements.

Distributed systems are a network of independent computers that work together to achieve a common goal. Security can be maintained through encryption, authentication, access control, and monitoring.

• Distributed systems consist of multiple computers that communicate and coordinate actions to achieve a common goal.

• Security in distributed systems can be maintained through encryption of data in transit and at rest.

• Authentication mechanisms such as passwords, tokens, or biometrics ...read more

Container orchestration tools are crucial for managing the deployment, scaling, and monitoring of large complex systems.

• Container orchestration tools help automate the deployment and scaling of containerized applications, making it easier to manage large complex systems.

• They provide features like service discovery, load balancing, health checks, and auto-scaling, which are essential for ensuring high availability and performance.

• Popular container orchestration tools include K...read more

Backend architecture design for an online e-commerce platform involves designing a scalable, secure, and reliable system.

• Choose a suitable database management system (DBMS) based on the requirements

• Use a microservices architecture to break down the system into smaller, independent services

• Implement caching mechanisms to improve performance

• Ensure data security by implementing encryption, access control, and regular backups

• Use load balancing and auto-scaling to handle traffic s...read more

Internal implementation of HashMap and Publisher-Subscriber concept in core Java.

• HashMap in Java is implemented using an array of linked lists and hash codes to store key-value pairs.

• Publisher-Subscriber pattern in Java involves one object (the publisher) sending updates to multiple other objects (subscribers).

• Polymorphism in Java allows objects of different classes to be treated as objects of a common superclass.

• Abstraction in Java involves hiding the implementation details ...read more

Map and unordered_map are associative containers that store elements in key-value pairs.

• Map is implemented as a balanced binary tree while unordered_map is implemented as a hash table.

• Map stores elements in sorted order based on the key while unordered_map does not guarantee any specific order.

• Map has a slower insertion and deletion time complexity than unordered_map.

• Map is useful when we need to maintain elements in a sorted order while unordered_map is useful when we need f...read more

Various automation frameworks like keyword-driven, data-driven, hybrid, and behavior-driven are commonly used in software testing.

• Keyword-driven framework: Tests are written using keywords and actions.

• Data-driven framework: Tests are driven by data sets.

• Hybrid framework: Combination of multiple frameworks.

• Behavior-driven framework: Focuses on behavior of the system.

• Page Object Model (POM): Organizes code by separating web pages and their elements.