100+ Visa Interview Questions and Answers

Determine the maximum number of elements that can be made equal by performing at most K operations on an array of integers.

• Sort the array in non-decreasing order to easily identify the elements that need to be increased

• Calculate the difference between adjacent elements to determine the number of operations needed to make them equal

• Keep track of the total number of operations used and the maximum number of elements that can be made equal

Count the number of ways to reach target from source in a grid with 0s and 1s.

• Use dynamic programming to solve the problem efficiently.

• Traverse the grid using DFS or BFS to count the number of ways.

• Consider edge cases like when source and target are the same or when there is no path.

• Example: Given grid = [[0,0,0],[0,1,0],[0,0,0]], source = (0,0), target = (2,2), answer is 2.

• Example: Given grid = [[0,1],[0,0]], source = (0,0), target = (1,1), answer is 1.

Determine maximum profit with at most K transactions by buying and selling stocks on given days.

• Iterate through the array of prices while keeping track of the maximum profit achievable with at most K transactions.

• Use dynamic programming to store the maximum profit at each day and transaction count.

• Consider buying and selling stocks at each day to calculate the maximum profit.

• Return the maximum profit achievable with at most K transactions.

Comparing 2 basketball game scenarios with different number of trials and baskets required to win

• Calculate the probability of winning in each game scenario using binomial distribution formula

• Compare the probabilities to determine which game scenario is preferable

• In game1, the probability of winning is p. In game2, the probability of winning is the sum of probabilities of making 2 or 3 baskets

• If p is high, game1 is preferable. If p is low, game2 is preferable

• For example, if p ...read more

Find the number of distinct pairs of participants with a given difference in chosen numbers.

• Iterate through the array and for each element, check if the pair exists with the required difference 'K'.

• Use a hash set to keep track of unique pairs to avoid counting duplicates.

• Return the size of the hash set as the final count of distinct pairs.

Find the maximum length of a sub-array with adjacent differences of 0 or 1 in an array of integers.

• Iterate through the array and keep track of the current sub-array length with adjacent differences of 0 or 1.

• Update the maximum length encountered so far as you traverse the array.

• Return the maximum length found as the result.

The task is to determine the in-order traversal of a Binary Tree given in level order.

• Implement a function to perform in-order traversal of a Binary Tree

• Use recursion to traverse left subtree, visit root, and then traverse right subtree

• Handle null nodes denoted by -1 in the input

Design a Least Recently Used (LRU) cache data structure that supports get and put operations with capacity constraint.

• Use a combination of hashmap and doubly linked list to implement the LRU cache.

• Keep track of the least recently used item and evict it when the cache reaches its capacity.

• Update the position of an item in the cache whenever it is accessed to maintain the order of recently used items.

Check if a given string containing parentheses and asterisks is valid based on certain conditions.

• Iterate through the string and keep track of the count of left parentheses, right parentheses, and asterisks.

• Use a stack to keep track of the positions of left parentheses and asterisks.

• If at any point the count of right parentheses exceeds the count of left parentheses and asterisks, the string is invalid.

Count the total number of unique pairs in an array whose elements sum up to a given value.

• Use a hashmap to store the frequency of each element in the array.

• Iterate through the array and for each element, check if (Sum - current element) exists in the hashmap.

• Increment the count of pairs if the complement exists in the hashmap.

Find minimum cost to reach end of array by jumping with constraints

• Use dynamic programming to keep track of minimum cost at each index

• Iterate through the array and update the minimum cost based on reachable indices within K steps

• Calculate cost to jump from current index to reachable indices and update minimum cost accordingly

Tech stack for designing a scalable Uber-like service.

• Use microservices architecture for scalability and fault tolerance.

• Choose a cloud provider with auto-scaling capabilities.

• Use a load balancer to distribute traffic across multiple instances.

• Use a NoSQL database for high availability and scalability.

• Use message queues for asynchronous communication between services.

• Use containerization for easy deployment and management.

• Use caching to improve performance.

• Use monitoring and ...read more

The task is to find the length of the longest common subsequence between two given strings.

• Implement a function to find the longest common subsequence between two strings.

• Use dynamic programming to solve the problem efficiently.

• Iterate through the strings and build a matrix to store the lengths of common subsequences.

• Return the length of the longest common subsequence.

• Example: For input STR1 = 'abcde' and STR2 = 'ace', the longest common subsequence is 'ace' with a length of ...read more

Find the second most repeated word in an array of strings with unique frequencies.

• Iterate through the array and count the frequency of each word using a hashmap.

• Sort the hashmap by frequency in descending order.

• Return the second key in the sorted hashmap.

Determine if two nodes in a graph are connected directly or indirectly based on a given threshold value and queries.

• Iterate through each query and check if the nodes are connected based on the given conditions

• Use the concept of greatest common divisor (GCD) to determine connectivity

• Return a list of 1s and 0s indicating connectivity for each query

Given a special keyboard with four keys, determine the maximum number of 'A's that can be printed on the screen by pressing the keys 'N' times.

• Use dynamic programming to keep track of the maximum number of 'A's that can be printed at each step.

• At each step, consider the possibilities of pressing 'A', 'Ctrl-A', 'Ctrl-C', and 'Ctrl-V'.

• Optimally choose the sequence of keys to maximize the number of 'A's printed on the screen.

• Example: For N = 7, the optimal sequence is: A, A, A, ...read more

Design a service to aggregate multiple sources of data/documentation centrally.

• Identify sources of data/documentation

• Determine data aggregation method

• Design a centralized database to store aggregated data

• Develop a user-friendly interface to access the data

• Ensure data security and privacy

Find the minimum number of dice throws required to reach the last cell on a 'Snake and Ladder' board.

• Use Breadth First Search (BFS) algorithm to find the shortest path from start to end cell.

• Create a mapping of each cell to its corresponding row and column on the board.

• Consider the special cases of snakes and ladders while calculating the next possible moves.

• Keep track of visited cells to avoid revisiting them during the traversal.

The N Queens Problem involves finding all possible placements of N queens on an N x N chessboard where no two queens threaten each other.

• Use backtracking algorithm to explore all possible configurations.

• Keep track of rows, columns, and diagonals to ensure queens do not threaten each other.

• Generate all valid configurations and print them out.

• Consider edge cases like N = 1 or N = 2 where no valid configurations exist.

GET is used to request data from a server, while POST is used to submit data to a server.

• GET requests data from a specified resource, while POST submits data to be processed to a specified resource.

• GET requests are cached by browsers, while POST requests are not.

• GET requests can be bookmarked and shared, while POST requests cannot.

• GET requests have length restrictions, while POST requests do not.

• Example: Using GET to retrieve information from a database, and using POST to sub...read more

Visa is a global payments technology company that connects consumers, businesses, banks and governments in more than 200 countries and territories.

• Visa operates the world's largest retail electronic payments network.

• VisaNet, the company's global processing system, handles more than 65,000 transaction messages a second.

• Visa is constantly innovating to improve payment security and convenience, with initiatives such as Visa Checkout and tokenization.

• Visa is committed to financia...read more

Race condition is a situation where multiple threads/processes access and manipulate shared data simultaneously.

• It can be eliminated by using synchronization techniques like locks, semaphores, and mutexes.

• Another way is to use atomic operations that ensure the data is accessed and modified atomically.

• Using thread-safe data structures can also prevent race conditions.

• Example: Two threads trying to increment a shared variable simultaneously can cause a race condition.

• Example: U...read more

To scale a monolith architecture and improve response time, use horizontal scaling and implement caching.

• Implement horizontal scaling by adding more instances of the monolith application behind a load balancer

• Use a distributed cache to store frequently accessed data and reduce database queries

• Implement caching at different levels such as application-level caching, database query caching, and HTTP response caching

• Use a caching strategy based on the data access patterns and exp...read more

Need more context on the question to provide an answer.

• Please provide more information on the problem to be solved.

• Without context, it is difficult to provide a solution.

• Can you please provide more details on the problem statement?

Two trains starting from equator in opposite directions will not collide. Which train will have more wear and tear first?

• The train moving towards the east will have more wear and tear due to the rotation of the earth

• The train moving towards the west will have less wear and tear due to the rotation of the earth

• Air resistance will also affect the wear and tear of the trains

• The train moving towards the east will face more air resistance than the train moving towards the west

To create an immutable class in Java, make the class final, make all fields private and final, provide only getter methods, and do not provide any setter methods.

• Make the class final to prevent inheritance.

• Make all fields private and final to prevent modification.

• Provide only getter methods to access the fields.

• Do not provide any setter methods to modify the fields.

SOAP is a protocol, while REST is an architectural style for web services.

• SOAP is a protocol that uses XML for message format and relies on a request-response model.

• REST is an architectural style that uses standard HTTP methods like GET, POST, PUT, DELETE.

• SOAP is more rigid and requires more bandwidth, while REST is lightweight and flexible.

• SOAP has built-in security features like WS-Security, while REST relies on external security measures.

• SOAP is commonly used in enterprise...read more

Print the given Binary search tree in ascending order

• Traverse the left subtree recursively

• Print the root node

• Traverse the right subtree recursively

Chennai faces problems related to water scarcity, traffic congestion, and pollution.

• Water scarcity due to inadequate rainfall and poor management of water resources.

• Traffic congestion due to the increasing number of vehicles and poor road infrastructure.

• Pollution caused by industries, vehicular emissions, and improper waste disposal.

Merge two sorted arrays into the first array

• Start from the end of both arrays and compare elements

• Place the larger element at the end of the first array

• Continue this process until all elements are merged

Implement Binary Search Tree using given array of strings.

• Sort the array in ascending order

• Find the middle element and make it the root of the tree

• Recursively create left and right subtrees using the left and right halves of the array

• Repeat until all elements are added to the tree

Ajax calls allow for asynchronous communication between client and server without reloading the page.

• Ajax stands for Asynchronous JavaScript and XML

• Uses XMLHttpRequest object to send and receive data

• Allows for partial page updates without reloading the entire page

• Can handle data in various formats such as JSON, XML, HTML, and plain text

• Example: $.ajax({url: 'example.com', success: function(data){console.log(data)}});

Immutability in Java refers to the property of objects whose state cannot be changed once they are created.

• Immutability ensures that once an object is created, its state cannot be modified.

• Immutable objects are thread-safe and can be shared without the risk of data corruption.

• String class in Java is an example of an immutable class.

• To create an immutable class, make the class final, all fields private, and provide only getter methods.

Creating immutable in Java

• Use final keyword to make variables immutable

• Use private constructor to prevent object modification

• Use defensive copying to prevent modification of mutable objects

• Use enum to create immutable objects

• Use String class to create immutable strings

Design a cache class with get(), put(), and initialization methods.

• Define a class with a data structure to store key-value pairs.

• Implement a get() method to retrieve a value from the cache based on a given key.

• Implement a put() method to add or update a key-value pair in the cache.

• Implement an initialization method to set the initial capacity and eviction policy of the cache.

• Consider using a hash map or a linked list to store the key-value pairs efficiently.

• Handle cache size ...read more

Immutable is used in Java to create objects whose state cannot be changed after creation.

• Immutable objects are thread-safe and can be shared without the risk of data corruption.

• Examples of immutable classes in Java include String, Integer, and LocalDate.

• Immutable objects can be created using the final keyword, constructor initialization, and static factory methods.

React lifecycle functions are methods that are automatically called at specific points in a component's life cycle.

• Mounting: constructor, render, componentDidMount

• Updating: render, componentDidUpdate

• Unmounting: componentWillUnmount

Visa is a payment processing company that facilitates electronic funds transfers globally.

• Visa operates a network that connects financial institutions, merchants, and consumers worldwide.

• The company provides payment products and services, including credit and debit cards, prepaid cards, and digital wallets.

• Visa's payment processing system involves authorization, clearing, and settlement of transactions.

• To design a scalable file access system like Dropbox or Google Drive, one ...read more

My project is a mobile app that helps users track their daily exercise and nutrition.

• Ensure the app is user-friendly and intuitive

• Implement a secure login and authentication system

• Integrate with fitness trackers and nutrition databases

• Perform thorough testing and bug fixing

• Consider scalability and performance optimization

• Implement a monetization strategy for commercial use

BUS topology is preferred for small networks while ring topology is preferred for larger networks.

• BUS topology is easier to install and maintain than ring topology.

• Ring topology is more fault-tolerant than BUS topology.

• BUS topology is suitable for small networks with few devices while ring topology is suitable for larger networks with many devices.

• Ring topology is more expensive than BUS topology.

• Examples of BUS topology include Ethernet and USB while examples of ring topolog...read more

The Observer Pattern is a behavioral design pattern where an object (subject) maintains a list of dependents (observers) that are notified of any state changes.

• Allows for one-to-many dependency between objects

• When the subject's state changes, all observers are automatically notified and updated

• Commonly used in event handling systems and GUI frameworks

OOPS concepts include abstraction, inheritance, polymorphism, and encapsulation.

• Abstraction: Hiding implementation details and showing only necessary information.

• Inheritance: Creating new classes from existing ones, inheriting properties and methods.

• Polymorphism: Using a single method to perform different actions based on the object type.

• Encapsulation: Binding data and methods together, protecting data from outside interference.

The time taken by the kth person to collect n number of tickets can be calculated using a formula.

• Use the formula: time = (n - 1) * k

• Subtract 1 from n because the first person doesn't need to wait for anyone

• Multiply the result by k to get the time taken by the kth person

• Example: If n = 5 and k = 3, the time taken by the 3rd person would be (5 - 1) * 3 = 12

A credit/debit card typically contains the cardholder's name, card number, expiration date, and security code.

• Cardholder's name

• Card number

• Expiration date

• Security code/CVV

• Card issuer logo

• Magnetic stripe

• Chip

• Contactless payment symbol

Observer pattern is a design pattern in which an object maintains a list of its dependents and notifies them automatically of any state changes.

• Also known as publish-subscribe pattern

• Used in event-driven systems

• Allows loose coupling between objects

• Example: A weather station broadcasts weather updates to multiple displays

• Example: A stock market ticker notifies multiple investors of stock price changes

Unit testing involves testing individual units of code to ensure they function as expected.

• Identify the individual units of code to be tested

• Create test cases for each unit, covering all possible scenarios

• Execute the tests and analyze the results

• Refactor the code as necessary based on the test results

A singleton class is a class that can only have one instance created throughout the entire application.

• Singleton classes have a private constructor to prevent multiple instances from being created.

• They typically provide a static method to access the single instance.

• Commonly used for logging, database connections, and configuration settings.

Testing principles ensure software quality, while design principles guide software development.

• Testing principles include unit testing, integration testing, and acceptance testing.

• Design principles include SOLID, DRY, and KISS.

• Testing principles ensure that software meets requirements and is free of defects.

• Design principles guide software development to be modular, maintainable, and scalable.

I primarily use SSH (Secure Shell) to connect servers.

• SSH (Secure Shell) is a widely used application for securely connecting to servers

• Other applications like PuTTY, OpenSSH, and WinSCP can also be used for server connections

REST is lightweight and uses HTTP while SOAP is XML-based and has more features.

• REST uses HTTP methods like GET, POST, PUT, DELETE while SOAP uses XML messaging.

• REST is stateless while SOAP can maintain state.

• REST is faster and easier to use while SOAP is more secure and reliable.

• REST is used for web services while SOAP is used for enterprise-level services.

• Example of REST: Twitter API. Example of SOAP: Amazon Web Services.

A multi-layered approach is needed to prevent DoS and network attacks.

• Implement firewalls and intrusion detection systems

• Use load balancers to distribute traffic

• Regularly update software and security patches

• Limit access to sensitive data and systems

• Educate employees on safe browsing habits and phishing scams

Dependency injection is a design pattern where components are given their dependencies rather than creating them internally.

• Allows for easier testing by providing mock dependencies

• Promotes loose coupling between components

• Improves code reusability and maintainability

• Examples: Constructor injection, Setter injection, Interface injection

Custom data structure for array of strings

• Use a trie data structure to efficiently store and search for strings

• Implement methods for adding, removing, and searching for strings in the trie

• Consider optimizing the trie for memory usage and performance

Understanding internal workings of DB structures and indices is crucial for optimizing database performance.

• DB structures refer to how data is organized within a database, such as tables, columns, and relationships.

• Indices are data structures that improve the speed of data retrieval operations by providing quick access to specific data values.

• Understanding how indices work can help in optimizing query performance by reducing the number of rows that need to be scanned.

• Common t...read more

Padding is the space inside the border of an element, while margin is the space outside the border.

• Padding is used to create space between the content and the border of an element.

• Margin is used to create space between the border of an element and other elements.

• Padding affects the size of the content area, while margin affects the positioning of the element.

• Example: padding: 10px will create 10 pixels of space inside the border of an element.

• Example: margin: 20px will create...read more

Data mining on VISA data can provide insights on consumer spending patterns and fraud detection.

• Identifying consumer spending habits and preferences

• Detecting fraudulent transactions and patterns

• Analyzing purchasing trends and market behavior

• Predicting customer churn and loyalty

• Optimizing marketing campaigns and personalized offers

Immutable in Java refers to objects whose state cannot be changed after creation.

• String, Integer, and other wrapper classes are immutable in Java.

• Immutable objects are thread-safe and can be shared without synchronization.

• To create an immutable class, make all fields final and private, and don't provide setters.

• Examples of immutable classes in Java include LocalDate, LocalTime, and LocalDateTime.

These are three different programming problems that require different approaches to solve.

• N-Queens: placing N queens on an NxN chessboard so that no two queens threaten each other

• Snake and Ladder Problem: finding the minimum number of dice rolls to reach the end of a board with snakes and ladders

• Second Most Repeated Word in a Sequence: finding the second most frequently occurring word in a given sequence of words

Using pandas in Python to perform tasks for a Software Engineer interview question

• Import pandas library

• Read data from a CSV file using pandas

• Perform data manipulation and analysis using pandas functions

• Write the processed data back to a new CSV file

To modify a Gmail notifier, you can customize its appearance, add additional features, or integrate it with other applications.

• Customize the notifier's appearance by changing its color, font, or notification sound.

• Add additional features such as the ability to mark emails as read or reply directly from the notifier.

• Integrate the notifier with other applications like a task manager or calendar to display reminders or deadlines.

• Implement filters to only receive notifications fo...read more

Regression testing is the process of testing changes made to a software application to ensure that existing functionality still works.

• It is performed after making changes to the software

• It ensures that existing functionality is not affected by the changes

• It helps to catch any defects or bugs that may have been introduced

• It can be automated using testing tools

• Examples include retesting after bug fixes, testing after new features are added

GET and POST are HTTP methods used for sending data to a server.

• GET is used to retrieve data from a server

• POST is used to submit data to a server

• GET requests can be cached and bookmarked

• POST requests are not cached and cannot be bookmarked

• GET requests have length restrictions

• POST requests have no length restrictions

• GET requests are less secure than POST requests

Autocomplete in IDEs helps developers write code faster by suggesting code snippets and completing code as they type.

• Autocomplete should suggest code snippets based on the context of the code being written

• Autocomplete should prioritize suggestions based on frequency of use

• Autocomplete should also suggest variable and function names

• Autocomplete should be customizable to allow for user-defined snippets and suggestions

• Examples of IDEs with autocomplete include Visual Studio Code...read more

CORS stands for Cross-Origin Resource Sharing. It is a security feature implemented in web browsers to restrict access to resources from different origins.

• CORS allows web servers to specify which origins are allowed to access its resources

• It is implemented using HTTP headers

• CORS prevents malicious websites from accessing sensitive data from other websites

• Examples of resources that may be restricted by CORS include cookies, scripts, and APIs

Supporting application for SSO enablement involves configuring authentication settings, integrating with identity providers, and testing functionality.

• Configure authentication settings within the application to enable SSO

• Integrate the application with identity providers such as Okta, Azure AD, or PingFederate

• Test the SSO functionality to ensure seamless user experience

• Provide documentation and training for users on how to use SSO with the application

Enable SSO for SaaS applications by integrating with identity providers and configuring authentication protocols.

• Integrate with identity providers such as Okta, Azure AD, or Google Workspace

• Configure authentication protocols like SAML, OAuth, or OpenID Connect

• Implement single sign-on functionality in the application code

• Ensure secure communication between the application and the identity provider

Yes, I have experience in taking care of the Authorization part in various projects.

• Implemented role-based access control (RBAC) to manage user permissions

• Configured and managed authentication protocols such as OAuth and SAML

• Worked on setting up access control lists (ACLs) for network security

• Experience with managing user roles and permissions in Active Directory

• Utilized single sign-on (SSO) solutions for seamless user authentication

SDLC refers to the process of software development. Different models include Waterfall, Agile, Spiral, and V-Model.

• Waterfall model follows a linear sequential approach with distinct phases like planning, design, development, testing, and maintenance.

• Agile model emphasizes on iterative and incremental development with continuous feedback and collaboration between cross-functional teams.

• Spiral model combines the elements of both Waterfall and Agile models with risk analysis and...read more

Replace each element with the greatest element on its right side in the array

• Loop through the array from right to left

• Keep track of the maximum element seen so far

• Replace the current element with the maximum element seen so far

• Return the modified array

Singleton is a design pattern that restricts the instantiation of a class to a single object.

• Singleton ensures that only one instance of a class exists in the entire application.

• It provides a global point of access to the instance.

• Commonly used in scenarios where a single instance needs to coordinate actions across the system.

• Example: Database connection manager, logger, configuration manager.

I am expecting a competitive salary based on my experience and the responsibilities of the role.

• I am open to negotiation based on the company's budget and benefits package.

• I have researched the average salary range for this position in the industry and location.

• I am confident in my skills and experience and believe I can bring value to the company.

• I am looking for a fair and reasonable compensation package that reflects my contributions to the company's success.

I will go into great depth to understand the system design, including analyzing all components and interactions.

• I will thoroughly review the system architecture, including all components and their interactions.

• I will analyze the data flow within the system to understand how information is processed and shared.

• I will consider scalability and performance requirements to ensure the system can handle future growth.

• I will collaborate with stakeholders and technical experts to gain...read more

JCube is a Java library for creating and manipulating Rubik's Cube puzzles.

• JCube provides classes for representing Rubik's Cube puzzles and algorithms for solving them.

• It supports various cube sizes and can generate random scrambles.

• JCube can be used in Java applications or as a standalone command-line tool.

• It is open source and available on GitHub.

I have experience working with both connected and disconnected applications.

• I have experience developing applications that can function both online and offline.

• I have worked on projects where data synchronization is crucial for seamless user experience.

• Examples include mobile apps that can work offline and sync data when connected to the internet.

AJAX allows web pages to be updated asynchronously by exchanging data with a web server behind the scenes.

• AJAX stands for Asynchronous JavaScript and XML.

• It allows web pages to update content without reloading the entire page.

• AJAX uses XMLHttpRequest object to send and receive data from a server.

• Commonly used in web applications to provide a more responsive user experience.

Given an array of integers, find two numbers that add up to a given target value.

• Use a hash map to store the difference between the target value and each element in the array.

• Iterate through the array and check if the current element exists in the hash map.

• If it does, return the indices of the two numbers.

• If no solution is found, return an empty array.

I handle change management by implementing structured processes, communication, and stakeholder involvement.

• Implementing a change management process to track and document changes

• Communicating changes effectively to all stakeholders

• Involving key stakeholders in decision-making and planning

• Ensuring proper testing and validation of changes before implementation

RTO stands for Recovery Time Objective in disaster recovery, representing the targeted duration of time within which a business process must be restored after a disaster.

• RTO is a crucial metric in disaster recovery planning, indicating the maximum acceptable downtime for a system or process.

• It helps organizations determine the resources and strategies needed to recover from a disaster within a specific timeframe.

• For example, if a company sets an RTO of 4 hours for its critica...read more

A class in Java is a blueprint or template for creating objects that encapsulate data and behavior.

• A class can contain fields, methods, constructors, and nested classes

• Objects are instances of a class

• Inheritance allows a class to inherit properties and methods from another class

• Polymorphism allows objects of different classes to be treated as if they are of the same class

• Example: class Car { String make; int year; void start() { ... } }

• Example: Car myCar = new Car(); myCar.ma...read more

Software engineering principles are the best practices and guidelines for developing high-quality software.

• Software should be designed with modularity and scalability in mind.

• Code should be well-documented and easy to read.

• Testing and debugging should be an integral part of the development process.

• Version control should be used to manage code changes.

• Security and privacy should be considered throughout the development lifecycle.

A circular linked list is a data structure where the last node points back to the first node, forming a loop.

• Create a Node class with data and next pointer

• Initialize the head node and set its next pointer to itself

• To add a node, create a new node and set its next pointer to the head node's next pointer, then update the head node's next pointer to the new node

• To traverse the circular linked list, start from the head node and continue until reaching the head node again

Digital signatures and digital certificates are cryptographic tools used to verify the authenticity and integrity of digital messages or documents.

• Digital signatures use a private key to encrypt a hash of the message, providing authentication and integrity.

• Digital certificates are issued by a trusted third party, containing the public key of the certificate holder.

• Certificates are used to verify the authenticity of the digital signature and the identity of the sender.

• Common e...read more

Spring Boot API endpoint is a URL that exposes the functionality of a web service.

• API endpoints are the entry points for the client to access the server's resources.

• Spring Boot provides a simple and easy way to create RESTful APIs.

• Endpoints can be secured using Spring Security.

• Endpoints can be documented using Swagger or Spring REST Docs.

• Examples: /users, /products, /orders

A Singleton class is a class that can only have one instance at a time.

• It restricts the instantiation of a class to a single object.

• It provides a global point of access to that instance.

• It is often used in situations where a single object is required to coordinate actions across a system.

• Example: Database connection manager, Configuration manager, Logger manager.

Code a basic linked list

• Create a Node class with data and next pointer

• Create a LinkedList class with head pointer

• Implement methods to add, delete, and search nodes in the linked list

A binary tree is a data structure in which each node has at most two children.

• Start with a root node

• Each node has a left and right child

• Nodes can be added or removed

• Traversal can be done in-order, pre-order, or post-order

Separate even and odd numbers in an array

• Iterate through the array and check if each number is even or odd

• Create two separate arrays for even and odd numbers

• Add the even numbers to the even array and odd numbers to the odd array

• Return both arrays as the result

Reconciling GL and subledger involves identifying and resolving discrepancies between the two accounts.

• Compare transactions in GL and subledger to identify discrepancies

• Investigate any differences in balances or transactions

• Adjust entries in GL or subledger to reconcile the accounts

• Ensure proper documentation of reconciliation process

• Communicate with relevant stakeholders to resolve discrepancies

A timer can be implemented using a combination of system time and a loop that checks for elapsed time.

• Get the current system time at the start of the timer

• Enter a loop that continuously checks the difference between the current system time and the start time

• When the desired time has elapsed, perform the desired action or trigger an event

useEffect is a hook in React that allows you to perform side effects in functional components.

• useEffect is used to handle side effects in React components.

• It takes two arguments: a function and an optional array of dependencies.

• The function inside useEffect is executed after the component renders.

• The optional array of dependencies determines when the effect should run.

• If the array of dependencies is empty, the effect runs only once after the initial render.

• If the array of dep...read more

Yes, I have worked in an agile environment before.

• I have experience working in Scrum and Kanban methodologies

• I have participated in daily stand-up meetings, sprint planning, and retrospectives

• I have collaborated closely with developers, product owners, and other team members to deliver high-quality software

Various types of testing are used in projects to ensure quality and functionality.

• Unit testing: Testing individual components or units of code.

• Integration testing: Testing the interaction between different components or modules.

• System testing: Testing the entire system to ensure it meets the requirements.

• Performance testing: Testing the system's performance under different loads.

• Security testing: Testing the system's vulnerability to security threats.

• User acceptance testing: ...read more

Yes, I am experienced in vulnerability management.

• I have experience in identifying, prioritizing, and mitigating vulnerabilities in systems and networks.

• I am proficient in using vulnerability scanning tools such as Nessus, Qualys, and OpenVAS.

• I have implemented patch management processes to address vulnerabilities in a timely manner.

• I have conducted vulnerability assessments and penetration testing to identify weaknesses in systems.

• I have worked on creating and implementing s...read more

Microkernel is a minimalistic approach where only essential services are kept in kernel space while macrokernel has more services in kernel space.

• Microkernel has a small kernel with minimal services while macrokernel has a large kernel with many services.

• In microkernel, most services run in user space while in macrokernel, most services run in kernel space.

• Microkernel is more secure and reliable while macrokernel is faster and more efficient.

• Examples of microkernel-based oper...read more