70+ Interview Questions and Answers

The probability that three ants running on the edges of an equilateral triangle will never meet is 1/3.

• The ants will never meet if they all move in the same direction (clockwise or counterclockwise) at the same speed.

• The probability of this happening is 1/3, as each ant has two possible directions to choose from.

• Example: If one ant starts moving clockwise, the other two ants must also move clockwise to never meet.

Garbage collection is necessary to free up memory occupied by unused objects. Java uses automatic garbage collection.

• Garbage collection helps prevent memory leaks and improves performance.

• Java uses a mark-and-sweep algorithm to identify and remove unused objects.

• The JVM periodically checks for unused objects and frees up memory occupied by them.

• Developers can also manually trigger garbage collection using System.gc() method.

• Garbage collection can cause temporary pauses in the...read more

This is a classic puzzle where the solution lies in thinking outside the box.

• The bar is not a chocolate bar, but a bar of soap.

• Cut it twice means to make three pieces.

• The solution is to stack the three pieces on top of each other and use them for 7 days.

Auto and static are two storage classes in C. Auto variables are local to a function while static variables retain their value between function calls.

• Auto variables are created when a function is called and destroyed when the function ends

• Static variables are initialized only once and retain their value between function calls

• Auto variables have garbage value if not initialized while static variables are initialized to zero by default

I have worked with various communication technologies and protocols across different OSI layers.

• TCP/IP - fits in transport layer

• HTTP - fits in application layer

• Ethernet - fits in data link layer

• SMTP - fits in application layer

• UDP - fits in transport layer

OOPs in JavaScript is a programming paradigm that uses objects to represent real-world entities. Functional programming is a paradigm that uses functions to perform tasks.

• OOPs in JavaScript involves creating objects that have properties and methods.

• Functional programming involves creating functions that take input and produce output without modifying the input.

• OOPs focuses on encapsulation, inheritance, and polymorphism.

• Functional programming focuses on immutability, higher-o...read more

Event loop is a mechanism that allows JavaScript to perform non-blocking I/O operations.

• Event loop is responsible for handling asynchronous callbacks in JavaScript.

• Tasks in the queue can be either microtasks or macrotasks.

• Microtasks are executed before macrotasks.

• Examples of macrotasks include setTimeout, setInterval, and I/O operations.

• Examples of microtasks include Promise callbacks and mutation observer callbacks.

The internet is a global network of interconnected devices that communicate using standardized protocols.

• The internet is based on the TCP/IP protocol suite.

• Data is transmitted in packets across the network.

• The network model consists of layers, including the physical, data link, network, transport, and application layers.

• Routing protocols are used to direct packets to their destination.

• Examples of internet applications include email, web browsing, and video conferencing.

UDP is used in scenarios where speed is more important than reliability, such as online gaming and video streaming.

• UDP is a connectionless protocol that does not guarantee delivery of packets

• It is faster than TCP because it does not have to establish a connection before sending data

• UDP is commonly used in online gaming, video streaming, and VoIP applications

• It is also used for broadcasting and multicasting data to multiple recipients

I have worked on the Agile SDLC and primarily function as a Scrum Master.

• I have experience working in Agile environments, specifically using Scrum methodology.

• I have led daily stand-up meetings, sprint planning sessions, and retrospectives.

• I have collaborated with cross-functional teams to deliver high-quality software products on time.

• I have used tools like Jira and Trello to track progress and manage tasks.

Yes, I am familiar with TMF standards and have used them in previous projects.

• I have used TMF Reference Model for organizing and managing clinical trial documentation

• I am familiar with TMF structure and content requirements

• I have experience in implementing TMF standards to ensure compliance with regulatory guidelines

Telecom company vs Verizon comparison for Principal Engineer role

• Telecom companies may have a more traditional approach to business operations compared to Verizon's focus on innovation and technology

• Verizon may have a stronger emphasis on customer service and satisfaction

• Verizon's network infrastructure and technology advancements may be more advanced compared to some telecom companies

• Verizon's corporate culture and values may differ from those of a typical telecom company

Bubble sort is a simple sorting algorithm that repeatedly steps through the list, compares adjacent elements and swaps them if they are in the wrong order.

• Bubble sort has a worst-case and average complexity of O(n^2), where n is the number of items being sorted.

• It is not efficient for large lists and is generally used for educational purposes.

• Example: Sorting an array of strings in alphabetical order using bubble sort.

Program to find a missing number in Arrays

• Sort the array and iterate to find the missing number

• Use XOR operation to find the missing number

• Calculate the sum of all numbers and subtract from the sum of expected numbers to find the missing number

Callbacks hell is a situation where nested callbacks make code hard to read and maintain. Promises, observables, and async/await are solutions to this problem.

• Callbacks hell occurs when there are too many nested callbacks in code.

• Promises are a way to handle asynchronous operations in JavaScript.

• Observables are similar to promises but can handle multiple values over time.

• Async/await is a syntax for writing asynchronous code that looks like synchronous code.

Higher order functions are functions that take other functions as arguments or return functions as their result.

• Higher order functions allow for more flexible and reusable code.

• They can be used for tasks such as filtering, mapping, and reducing arrays.

• Examples include Array.prototype.map(), Array.prototype.filter(), and Array.prototype.reduce().

TCP is a connection-oriented protocol while UDP is connectionless.

• TCP provides reliable data transfer while UDP does not guarantee reliability.

• TCP uses flow control and congestion control while UDP does not.

• TCP is slower than UDP due to the overhead of establishing and maintaining a connection.

• UDP is faster than TCP for applications that can tolerate data loss such as video streaming or online gaming.

I have experience working with OSS and BSS systems such as NetCracker, Amdocs, and CSG.

• NetCracker

• Amdocs

• CSG

The Collection Framework is a unified architecture for representing and manipulating collections in Java.

• It provides interfaces like List, Set, Queue, etc. for storing and manipulating collections of objects.

• It also provides concrete classes like ArrayList, HashSet, PriorityQueue, etc. that implement these interfaces.

• It supports algorithms like sorting, searching, and shuffling on collections.

• It is a part of the Java Collections Framework.

• Example: List names = new ArrayList<>...read more

I would rate myself a 2 in C programming.

• I have a good understanding of basic syntax and data types.

• I am able to write simple programs and functions.

• However, I still have room for improvement in more advanced concepts like pointers and memory management.

Closure is a function that has access to variables in its outer scope, even after the outer function has returned.

• A closure can be used to create private variables and methods in JavaScript.

• Closures can be used to implement partial application and currying.

• Event listeners and callbacks often use closures to maintain state between function calls.

• Closures can be used to create memoized functions that cache their results for future use.

IC 555 timer is a versatile timer IC used in various applications like oscillators, timers, and flip-flops.

• IC 555 timer has three modes of operation: monostable, astable, and bistable.

• In monostable mode, the output is high for a fixed duration when triggered.

• In astable mode, the output oscillates between high and low states.

• In bistable mode, the output remains in either high or low state until triggered.

• IC 555 timer can be used in various applications like LED flashers, tone ...read more

End-to-end process flow across OSS and BSS involves order management, service activation, billing, and customer care.

• Order is placed by customer through self-service portal or customer service representative in OSS

• Order is validated, processed, and provisioned in OSS

• Service activation triggers in BSS, updating customer account and billing information

• Billing system generates invoice based on service usage and sends to customer

• Customer care system tracks customer interactions a...read more

Redux is a predictable state container for JavaScript apps.

• Redux is used for managing the state of an application.

• It is commonly used with React to manage the state of components.

• Redux uses a single store to manage the state of an entire application.

• Actions are dispatched to the store to update the state.

• Reducers are used to update the state based on the dispatched actions.

• Functional components can use the useSelector hook to access the state.

• Class components can use the conn...read more

I have extensive experience working with OSS and BSS systems in the telecommunications industry.

• Implemented and maintained OSS/BSS systems for network inventory management

• Developed custom solutions for billing and customer management using OSS/BSS platforms

• Integrated OSS/BSS systems with third-party applications for seamless operations

An abstract class is a class that cannot be instantiated and is used as a base class for other classes.

• An abstract class can have abstract and non-abstract methods.

• Abstract methods have no implementation and must be implemented by the subclass.

• A class can only extend one abstract class but can implement multiple interfaces.

• Abstract classes are used to provide a common interface for a group of related classes.

• Example: abstract class Animal { abstract void makeSound(); }

Compile time polymorphism is method overloading, while run time polymorphism is method overriding. Multiple inheritance is not supported in Java.

• Compile time polymorphism is achieved through method overloading, where multiple methods have the same name but different parameters.

• Run time polymorphism is achieved through method overriding, where a subclass provides a specific implementation of a method that is already defined in its superclass.

• Java does not support multiple inhe...read more

To check if two words are anagrams, compare the sorted characters of each word.

• Sort the characters of both words

• Compare the sorted characters to check if they are equal

• Handle edge cases like different lengths or special characters

Data helps in product management by providing insights into user behavior and preferences.

• Data helps in identifying user needs and preferences, which can inform product development.

• Data can be used to track user behavior and identify areas for improvement.

• Data can also be used to measure the success of product changes and inform future decisions.

• In a previous role, I worked in a data-driven environment where we used A/B testing to inform product decisions.

• We also regularly an...read more

User stories should be written in a simple and concise manner, focusing on the user's needs and goals.

• Start with 'As a [user], I want [goal], so that [reason]' format

• Include acceptance criteria for developers to understand the requirements

• Use personas to create realistic user stories

• Prioritize user stories based on business value and complexity

• Collaborate with stakeholders to refine and validate user stories

Constructor can be declared static or non-static depending on the use case.

• If a constructor is declared static, it means it can be called without creating an instance of the class.

• Static constructors are used to initialize static fields of the class.

• Non-static constructors are used to initialize instance fields of the class.

• If a class has both static and non-static constructors, the non-static constructor is called when an instance of the class is created.

I would suggest adding a feature to allow users to customize their dashboard based on their preferences.

• The app should allow users to choose which information they want to see on their dashboard

• Users should be able to rearrange the order of the information displayed

• The app should also allow users to set alerts for specific market events

• This feature would improve user experience by providing more personalized information

• For example, a user who is primarily interested in crypto...read more

Yes, I have experience with REST API and Microservices.

• Developed RESTful APIs using Node.js and Express framework

• Implemented Microservices architecture using Docker and Kubernetes

• Utilized Swagger for API documentation and testing

• Worked on integrating third-party APIs in microservices architecture

Locators are used to identify web elements in Selenium.

• Locators are used to find and interact with web elements on a web page.

• There are several types of locators in Selenium, including ID, name, class name, tag name, link text, and partial link text.

• For example, to find an element with the ID 'username', you would use the ID locator: driver.findElement(By.id('username'));

Browsers use rendering engines to interpret HTML, CSS, and JavaScript to display web pages.

• Browsers use rendering engines to interpret HTML, CSS, and JavaScript.

• The rendering engine parses the HTML and creates a DOM tree.

• The rendering engine then applies CSS rules to the DOM tree to create a render tree.

• The render tree is then laid out to determine the position of each element on the page.

• Finally, the rendering engine paints the render tree on the screen.

• JavaScript can manipu...read more

Output of the code in JavaScript

• Need to see the code to determine output

• Output can vary based on input and logic

• Can use console.log() to print output

I evaluate factors such as scalability, compatibility, cost, and user experience to choose the best technology for a product.

• Assess the scalability of the technology to ensure it can handle future growth

• Consider compatibility with existing systems and technologies

• Evaluate the cost of implementing and maintaining the technology

• Prioritize user experience by choosing technology that enhances usability and performance

Program to reverse a string

• Use a loop to iterate through the string and append each character to a new string in reverse order

• Alternatively, use built-in string reversal functions in some programming languages

To find a one element Xpath in Amazon.com

• Inspect the element in the browser

• Right-click on the element and select 'Copy XPath'

• Use the copied XPath in your code

Expected CTC should be justified if greater than 30%

• Highlighting additional skills or experience that justify the higher salary

• Explaining the market demand for the role and the competitive salary range

• Demonstrating the value you bring to the company that justifies the higher compensation

An explicit constructor is a constructor that is defined with the 'explicit' keyword.

• It is used to prevent implicit conversions from the constructor's parameter type to the class type.

• It requires the constructor to be called explicitly with the class name and constructor arguments.

• It is commonly used to avoid unexpected type conversions and improve code clarity.

An interface in Java is a collection of abstract methods and constants that can be implemented by a class.

• An interface is declared using the interface keyword.

• It can be implemented by any class using the implements keyword.

• All methods in an interface are implicitly public and abstract.

• Interfaces can also contain constants, which are implicitly public, static, and final.

• Interfaces are used to achieve abstraction and provide a way for unrelated classes to communicate with each ...read more

I have experience with scikit-learn, TensorFlow, and Keras.

• Scikit-learn for traditional machine learning algorithms such as regression and classification

• TensorFlow for deep learning models such as neural networks

• Keras for building and training deep learning models quickly and easily

Prioritisation of features involves evaluating impact, effort, and alignment with business goals. Decision maker varies based on company structure.

• Prioritisation is based on impact on users, business goals, and resources available.

• Effort required to implement the feature is also considered.

• Alignment with overall product strategy and roadmap is crucial.

• Decision maker can be product manager, stakeholders, or cross-functional team.

• Examples: High impact features with low effort m...read more

Relative XPath is a way to locate elements in XML or HTML documents based on their position relative to other elements.

• Relative XPath uses the relationships between elements to navigate the document structure.

• It is more flexible than absolute XPath as it adapts to changes in the document's structure.

• Relative XPath expressions start with a reference to an element and then use various axes and predicates to locate the desired element.

• Example: //div[@class='container']/a[2] sele...read more

Selenium automation can control Chrome browser capabilities such as handling pop-ups, cookies, and browser settings.

• Selenium can handle pop-ups and alerts using the switchTo() method

• Cookies can be managed using the addCookie() and deleteCookie() methods

• Browser settings can be modified using the ChromeOptions class

• Examples: disabling images, setting the browser window size, and using headless mode

Yes, I have written a whitepaper on the implementation of machine learning algorithms in cybersecurity.

• Researched various machine learning algorithms commonly used in cybersecurity

• Analyzed the effectiveness of different algorithms in detecting and preventing cyber threats

• Discussed practical implementation strategies for integrating machine learning into existing cybersecurity systems

Yes, I have registered two patents related to renewable energy technologies.

• Patent 1: Solar panel design for increased efficiency

• Patent 2: Wind turbine blade design for improved performance

Filter external prefixes entering OSPF domain by using distribute-list or prefix-list

• Use distribute-list or prefix-list to filter external prefixes entering OSPF domain

• Create an access-list to match the external prefixes that need to be filtered

• Apply the distribute-list or prefix-list to the OSPF process on the specific interface

• Verify the filtering by checking OSPF neighbor relationships and routing table

As a frequent traveler, I want to be able to easily book and manage my hotel reservations.

• User can search for hotels based on location, dates, and price range.

• User can view hotel details, including amenities and photos.

• User can book a room and receive confirmation.

• User can manage their reservations, including modifying or cancelling bookings.

• User can leave reviews and ratings for hotels they have stayed at.

• User can earn rewards or loyalty points for booking through the platfo...read more

Hadoop is a distributed open-source framework for storing and processing large datasets, while GCP (Google Cloud Platform) is a cloud computing service that offers various data processing and storage solutions.

• Consider the size and complexity of your data: Hadoop is better suited for large-scale batch processing, while GCP offers more flexibility and scalability for various types of workloads.

• Evaluate your team's expertise: Hadoop requires specialized skills in managing and m...read more

Handling conflicts and discussions involves active listening, empathy, open communication, and finding common ground.

• Practice active listening to understand the other person's perspective

• Show empathy and try to see the situation from their point of view

• Communicate openly and honestly to express your own thoughts and feelings

• Focus on finding common ground and solutions that benefit both parties

• Stay calm and respectful, avoid escalating the conflict

Solving a magic cube involves arranging the colors on each face to match.

• Start by solving one face completely

• Then move on to the adjacent faces

• Use algorithms to move pieces around without disrupting solved faces

• Repeat until all faces are solved

Reverse a string without using functions in Java and Python

• Iterate through the string from end to start and store each character in a new array

• Join the characters in the new array to form the reversed string

Network flow in Nexus switches involves understanding vPC communication and troubleshooting SSH connectivity issues.

• Network flow in Nexus switches involves the movement of data packets between devices connected to the switches.

• vPC (Virtual Port Channel) communication in Nexus switches allows for link aggregation and redundancy by combining multiple physical links into a single logical link.

• Troubleshooting SSH connectivity issues on Nexus switches may involve checking the SSH ...read more

Print the first and last letter of words from a list alternatively

• Iterate through the list of words

• For each word, print the first and last letter alternatively

Yes, I have extensive experience in automation including scripting, testing, and deployment.

• Developed automation scripts using tools like Selenium, Jenkins, and Puppet

• Implemented automated testing frameworks to improve efficiency and accuracy

• Utilized automation for continuous integration and deployment processes

• Experience with scripting languages such as Python, Bash, and PowerShell

Yes, I have extensive experience working with cloud technologies such as AWS, Azure, and Google Cloud.

• Experience in designing and implementing cloud infrastructure

• Proficient in using cloud services such as EC2, S3, and RDS

• Knowledge of cloud security best practices

• Experience with cloud automation tools like Terraform and Ansible

Yes, I have experience with devOps in previous roles.

• Implemented CI/CD pipelines to automate software delivery processes

• Utilized tools like Jenkins, Git, Docker, and Kubernetes for deployment and monitoring

• Worked closely with development and operations teams to streamline workflows

Core concepts of Spring include dependency injection, aspect-oriented programming, and Spring MVC. Spring Boot simplifies the setup and configuration of Spring applications. Java 8 introduced lambda expressions and streams, while Java 17 added features like sealed classes and pattern matching. Object-oriented programming concepts include inheritance, polymorphism, encapsulation, and abstraction.

• Spring core concepts: dependency injection, aspect-oriented programming, Spring MV...read more

ITIL stands for Information Technology Infrastructure Library. It is a set of best practices for IT service management.

• ITIL provides a framework for IT service management to align IT services with the needs of the business.

• It helps organizations improve efficiency, reduce costs, and provide better customer service.

• ITIL consists of a series of publications that provide guidance on the provision of quality IT services.

• Examples of ITIL processes include incident management, chan...read more

Security groups control inbound/outbound traffic while NAT gateway allows instances in private subnets to access internet.

• Security groups act as a virtual firewall for instances and control inbound/outbound traffic based on rules defined by the user.

• NAT gateway allows instances in private subnets to access the internet while keeping them secure by not exposing their IP addresses to the internet.

• Security groups are associated with instances while NAT gateway is associated with...read more

I can value add by leveraging my expertise in strategic planning, problem-solving, and team leadership to drive successful project outcomes.

• Developing and implementing strategic plans to achieve project goals

• Utilizing problem-solving skills to overcome challenges and obstacles

• Leading and motivating teams to maximize productivity and collaboration

OOP stands for Object-Oriented Programming. OOPs concepts are the principles of OOP such as inheritance, encapsulation, polymorphism, and abstraction.

• OOP is a programming paradigm based on the concept of objects, which can contain data in the form of fields and code in the form of procedures.

• OOPs concepts include inheritance, where a class can inherit properties and behavior from another class.

• Encapsulation is the bundling of data with the methods that operate on that data, p...read more

A pem file contains both the private key and the certificate, while a key file only contains the private key.

• A pem file is used for SSL/TLS certificates

• A key file is used for SSH authentication

• Pem files can be converted to key files using OpenSSL

• Pem files are often used in web servers like Apache and Nginx

Microservices are a software development technique where applications are composed of small, independent services that communicate over well-defined APIs.

• Microservices break down applications into smaller, loosely coupled services

• Each service is responsible for a specific function and can be developed, deployed, and scaled independently

• Communication between services is typically done through APIs

• Examples include Netflix, Amazon, and Uber, which use microservices architecture ...read more

One of my weaknesses is that I tend to be overly critical of my own work.

• I have a tendency to overanalyze my projects, which can sometimes lead to delays in completion.

• I am working on improving my self-confidence to trust my abilities more.

• I have learned to seek feedback from others to gain different perspectives and improve my work.

Excel formulas are used to perform calculations and manipulate data in spreadsheets.

• Formulas start with an equal sign (=)

• Functions can be used in formulas to perform specific calculations

• Cell references can be used in formulas to reference data in other cells

• Formulas can be copied and pasted to other cells

• Examples: SUM, AVERAGE, IF, VLOOKUP