50+ WNS Interview Questions and Answers

Services in Angular are singleton objects that provide functionality to components. They can be called using dependency injection.

• Services are used to share data and functionality across multiple components

• They can be created using the 'ng generate service' command

• Services can be injected into components using the constructor

• To call a service API, use Angular's HttpClient module

• Data can be bound to components using property binding or two-way binding

Concurrent hashmap allows multiple threads to access and modify the map concurrently without causing data inconsistency.

• Concurrent hashmap is thread-safe and allows multiple threads to access and modify the map concurrently.

• It uses a technique called lock striping to divide the map into segments and apply locks to each segment instead of the entire map.

• This allows multiple threads to access different segments of the map concurrently without causing data inconsistency.

• Concurre...read more

Using Java streams to print odd numbers between 1 to 10 and greater than 5

• Use IntStream.range() to generate numbers from 1 to 10

• Filter the numbers using filter() to get odd numbers

• Use filter() again to get numbers greater than 5

• Print the numbers using forEach()

Hibernate framework provides ORM capabilities, simplifies database access, and improves performance.

• Hibernate reduces boilerplate code by providing ORM capabilities.

• It simplifies database access by abstracting away the underlying SQL.

• Hibernate improves performance by caching data and reducing database round trips.

• It supports lazy loading, which improves performance by loading data only when needed.

• Hibernate supports multiple database vendors and provides transaction managemen...read more

Handling exceptions in microservices, config server, ClassNotFoundException vs NoClassDefException

• 1. Exception handling in microservices involves using try-catch blocks to catch and handle exceptions at the service level.

• 2. Config server is a centralized server that stores configuration information for microservices, allowing them to retrieve configurations at runtime.

• 3. ClassNotFoundException occurs when a class is not found at runtime, while NoClassDefFoundError occurs when...read more

To call one webservice from another, use the endpoint URL and pass required parameters.

• Identify the endpoint URL of the webservice to be called

• Pass the required parameters to the endpoint URL

• Handle the response from the webservice

• Ensure proper error handling and logging

EC2 is a virtual server in the cloud, S3 is a scalable storage service, and Lambda is a serverless computing service.

• EC2 (Elastic Compute Cloud) provides resizable compute capacity in the cloud.

• S3 (Simple Storage Service) is object storage built to store and retrieve any amount of data.

• Lambda allows you to run code without provisioning or managing servers.

• Examples: EC2 can be used to host web applications, S3 can store files and data backups, Lambda can run code in response t...read more

Developed custom functionality for various projects.

• Created a custom payment gateway integration for an e-commerce platform.

• Implemented a personalized recommendation system based on user preferences for a streaming service.

• Developed a custom data visualization tool for analyzing sales data in a retail application.

To consume a web service in an application, use HTTP requests to send and receive data.

• Identify the web service endpoint and its API documentation

• Choose a programming language and framework to make HTTP requests

• Send HTTP requests to the web service endpoint with required parameters

• Receive and parse the response data from the web service

• Handle errors and exceptions appropriately

Hashmap is a data structure that stores key-value pairs using a hash function.

• Hashmap uses a hash function to map keys to their corresponding values.

• It has constant time complexity for insertion, deletion, and retrieval.

• Collisions can occur when two keys map to the same index, which is resolved using separate chaining or open addressing.

• Load factor determines the threshold for resizing the hashmap.

• Java's implementation of hashmap uses an array of linked lists for separate cha...read more

Record Triggered Flow is a type of Flow in Salesforce that is triggered when a record is created or updated.

• Record Triggered Flow is used to automate processes in Salesforce based on changes to records.

• It can be set to run before or after the record is saved.

• Record Triggered Flow can access and update related records as well.

• It is a powerful tool for automating complex business processes in Salesforce.

CPQ offers multiple products including Configure, Price, Quote, Contract Management, and Billing.

• Configure: Allows users to customize products based on customer needs

• Price: Calculates pricing based on configurations and discounts

• Quote: Generates quotes for customers based on configured products

• Contract Management: Manages contracts and agreements with customers

• Billing: Handles invoicing and payment processing

Bundle product is a group of related products sold together, while nested bundle is a bundle within a bundle.

• Bundle product is a collection of multiple products sold together as a single unit.

• Nested bundle is a bundle that contains another bundle within it.

• Example: A laptop bundle may include a laptop, a laptop bag, and a mouse. Within this bundle, there could be a nested bundle for extended warranty options.

Flow control shape in Boomi is used to control the flow of data within a process.

• Flow control shape allows you to route data based on conditions or criteria.

• It can be used to loop through a set of data multiple times until a certain condition is met.

• Examples include decision shape, branch shape, and stop shape.

Yes, I have worked on Amendment. It involves making changes to existing software code or documentation.

• Amendment involves modifying existing code or documentation to improve functionality or fix issues.

• Examples include updating a software feature to meet new requirements, fixing bugs in the code, or enhancing performance.

• Amendment may also involve revising documentation to reflect changes made to the software.

Renewal in CPQ refers to the process of renewing a contract or subscription for a product or service.

• Renewal in CPQ involves generating a renewal quote for an existing contract or subscription.

• The renewal flow typically includes reviewing the terms of the existing contract, making any necessary adjustments, and generating a new quote for the renewed contract.

• Customers may have the option to renew their contract for a specified period of time, with the possibility of negotiati...read more

Pricing Rule & Product Rule are mathematical concepts used in calculus to find derivatives of functions.

• Pricing Rule is used to find the derivative of a function that involves a product of two functions.

• Product Rule is used to find the derivative of a function that involves the product of two functions.

• Pricing Rule: (f(x)g(x))' = f'(x)g(x) + f(x)g'(x)

• Product Rule: (fg)' = f'g + fg'

MDQ (Multi Dimensional Quote) is a tool used in software development to estimate the effort required for a project by considering multiple dimensions.

• MDQ takes into account various factors such as complexity, team experience, technology stack, and project scope.

• It helps in providing a more accurate estimation of the time and resources needed for a project.

• For example, a project with a high complexity level and a new technology stack may have a higher MDQ compared to a project...read more

Different pricing methods include cost-plus pricing, value-based pricing, competition-based pricing, and dynamic pricing.

• Cost-plus pricing involves adding a markup to the cost of production.

• Value-based pricing sets prices based on the perceived value to the customer.

• Competition-based pricing involves setting prices based on competitors' prices.

• Dynamic pricing adjusts prices in real-time based on demand and other factors.

QCP is a software plugin used for calculating quotes for products or services.

• QCP is a tool used in sales or e-commerce platforms to provide accurate pricing information to customers.

• It can factor in variables such as quantity, discounts, taxes, and shipping costs to generate a final quote.

• QCP can be customized to fit the specific pricing structure and rules of a business.

• Examples of QCP include plugins for online shopping carts, insurance quoting systems, and subscription se...read more

To increase performance of an app, optimize code, improve database queries, utilize caching, and scale resources.

• Optimize code by identifying and fixing bottlenecks

• Improve database queries by indexing frequently accessed data

• Utilize caching to store frequently accessed data in memory for faster retrieval

• Scale resources by adding more servers or upgrading hardware

Magento follows the Model-View-Controller (MVC) design pattern. PHP latest version has improved performance and added features.

• Magento follows the Model-View-Controller (MVC) design pattern for separating concerns and improving maintainability.

• PHP latest version (7.4) has improved performance with JIT compiler and added features like typed properties and arrow functions.

• PHP older versions (5.x) have reached end-of-life and are no longer supported, posing security risks.

ConcurrentModificationException is a runtime exception thrown when an object is modified concurrently while being iterated.

• Occurs in Java when a collection is modified while being iterated over using an iterator

• Can be avoided by using concurrent collections like ConcurrentHashMap or CopyOnWriteArrayList

• Example: Attempting to remove an element from a list while iterating over it will throw ConcurrentModificationException

I have worked on 5 interfaces in my previous roles.

• Developed user interfaces for web applications using HTML, CSS, and JavaScript.

• Integrated APIs to create seamless interactions between different systems.

• Designed and implemented RESTful interfaces for data exchange.

• Worked on creating intuitive user interfaces for mobile applications.

• Collaborated with UX designers to improve user experience on interfaces.

Configuration attributes are settings that define the behavior of a software system.

• Configuration attributes can include parameters such as database connection strings, logging levels, and feature toggles.

• They are typically stored in configuration files or databases.

• Changing configuration attributes can alter the behavior of the software without modifying its code.

• Configuration attributes are used to customize the software for different environments or user preferences.

HashMap internally uses an array of linked lists to store key-value pairs, with keys hashed to determine the index.

• HashMap uses hashing to determine the index of key-value pairs in the array.

• Collisions are resolved by chaining, where multiple key-value pairs with the same hash are stored in a linked list at the same index.

• When retrieving a value, the key is hashed to find the index, then the linked list at that index is traversed to find the matching key.

Special Field in CPQ refers to a custom field that is unique to a specific use case or industry.

• Special fields can be used to capture industry-specific data or unique requirements.

• Examples include fields for pricing rules in the manufacturing industry or contract terms in the telecommunications industry.

SSIS is a data integration tool in SQL Server used for ETL operations.

• SSIS stands for SQL Server Integration Services.

• It is used for extracting, transforming, and loading data.

• SSIS packages can be created using SQL Server Data Tools.

• It supports various data sources and destinations.

• Control flow and data flow tasks are used to design SSIS packages.

Option constraints are restrictions placed on the values that can be assigned to an option in a software system.

• Option constraints define the valid range of values for an option.

• They can include minimum and maximum values, allowed data types, and specific values.

• For example, an option for selecting a color may have constraints that limit the choices to 'red', 'blue', or 'green'.

Pricing waterfall is a method used to analyze and optimize pricing strategies by breaking down the pricing process into different components.

• Pricing waterfall helps in understanding the impact of various factors on pricing decisions.

• It involves analyzing costs, competition, customer demand, and other market factors to determine the optimal pricing strategy.

• Examples of components in a pricing waterfall include fixed costs, variable costs, discounts, rebates, and promotions.

Package level setting refers to configuration settings that apply to an entire package of software components.

• Package level settings are configuration options that affect all components within a software package.

• These settings are typically defined at the package level and apply globally.

• Examples include setting default values for variables, defining access control rules, or specifying logging levels.

• Package level settings help maintain consistency and simplify management of ...read more

Guided selling is a sales technique where the salesperson guides the customer through the buying process, offering personalized recommendations and advice.

• Involves salesperson providing personalized recommendations to customers

• Helps customers make informed decisions during the buying process

• Often used in e-commerce websites to suggest products based on customer preferences

Angular is a popular front-end framework for building web applications.

• Angular is developed and maintained by Google.

• It uses TypeScript for building applications.

• Angular provides features like two-way data binding, dependency injection, and routing.

• Components, services, and modules are key building blocks in Angular.

• Angular CLI is a command-line tool for creating and managing Angular projects.

I handle authentication using industry-standard protocols and encryption methods.

• Utilize OAuth or OpenID Connect for secure authentication

• Implement multi-factor authentication for added security

• Store user credentials securely using encryption

• Regularly update authentication mechanisms to address any vulnerabilities

Different scopes of beans refer to their visibility and accessibility within an application.

• Beans can have different scopes such as singleton, prototype, request, session, and global session.

• Singleton scope means only one instance of the bean is created and shared throughout the application.

• Prototype scope means a new instance of the bean is created every time it is requested.

• Request scope means a new instance of the bean is created for every HTTP request.

• Session scope means ...read more

Batch APEX is a feature in Salesforce that allows developers to process records in bulk using Apex code.

• Batch APEX is used to handle large volumes of data in Salesforce.

• It is commonly used for tasks like data cleansing, data migration, and data processing.

• Batch APEX classes implement the Database.Batchable interface and are executed asynchronously.

• Developers can monitor and manage Batch APEX jobs through the Salesforce user interface.

Drill down is navigating from summary data to detailed data, while drill through is navigating from one report to another.

• Drill down allows users to see more detailed information by clicking on a summary data point.

• Drill through allows users to navigate from one report to another, typically by clicking on a hyperlink.

• Drill down is used to explore data within a single report, while drill through is used to navigate between different reports.

• Example of drill down: clicking on a...read more

A discount schedule is a set of rules or guidelines that determine the amount of discount a customer receives based on various factors.

• Discount schedules can be based on factors such as quantity purchased, customer loyalty, or promotional events.

• For example, a discount schedule may offer a 10% discount for purchases of 10 items or more.

• Another example could be a loyalty program where customers receive increasing discounts based on their total purchase amount over time.

Quote to Cash Flow is the process of generating revenue from the initial quote to the final payment.

• Quote to Cash Flow involves the entire sales process from creating a quote for a product or service to receiving payment for that product or service.

• It includes activities such as quoting, invoicing, order fulfillment, and payment collection.

• The goal of Quote to Cash Flow is to streamline the sales process and improve cash flow for the business.

• Example: A customer requests a qu...read more

Usages based product refers to a pricing model where customers are charged based on their usage of the product or service.

• Customers are charged based on the amount or frequency of their usage.

• Common in industries like cloud computing, SaaS, and utilities.

• Examples include pay-as-you-go cloud services, metered electricity usage, and usage-based insurance.

Arrow functions are a concise way to write functions in JavaScript.

• Arrow functions have a shorter syntax compared to traditional function expressions.

• They do not have their own 'this', 'arguments', 'super', or 'new.target'.

• Arrow functions are best suited for non-method functions.

• Example: const add = (a, b) => a + b;

Performance improvement for application involves optimizing code, database queries, and server configurations.

• Identify and optimize slow database queries

• Implement caching mechanisms to reduce redundant calculations

• Use efficient algorithms and data structures

• Optimize server configurations for better resource utilization

ADF stands for Application Development Framework. It is a Java-based framework used for building enterprise applications.

• ADF provides a visual and declarative development experience for building web and mobile applications.

• It includes a set of pre-built components and services for common enterprise application requirements.

• ADF supports multiple data sources and provides data visualization and reporting capabilities.

• It also includes security features such as authentication and...read more

A service is a piece of software that performs specific tasks or functions to support other software applications.

• Services can be used to handle background tasks, such as sending emails or processing data.

• Services can communicate with other services or applications through APIs.

• Examples of services include web servers, databases, and messaging queues.

AWS Lambda is a serverless computing service provided by Amazon Web Services.

• Serverless computing platform

• Allows running code without provisioning or managing servers

• Automatically scales based on incoming traffic

• Supports multiple programming languages like Node.js, Python, Java, etc.

• Pay only for the compute time consumed

Power BI is a business analytics service by Microsoft that provides interactive visualizations and business intelligence capabilities.

• Power BI allows users to connect to various data sources and create interactive reports and dashboards.

• It provides a wide range of visualization options such as charts, graphs, maps, and tables.

• Users can also create custom visuals using the Power BI developer tools.

• Power BI integrates with other Microsoft products such as Excel and SharePoint.

• I...read more

React Native is a framework for building mobile applications using JavaScript and React.

• Allows developers to write code once and deploy it on both iOS and Android platforms

• Utilizes native components for better performance and user experience

• Supports hot reloading for faster development iterations

const is used to declare a constant variable whose value cannot be changed, while var is used to declare a variable that can be reassigned.

• const is block-scoped, while var is function-scoped

• const must be initialized during declaration, var can be declared without initialization

• const is preferred for declaring variables that should not be reassigned, var is used for variables that may need to be reassigned

Render props is a pattern in React where a component's prop is a function that returns a React element.

• Render props allow components to share code and logic without inheritance.

• Render props can be used to pass data or functions from a parent component to a child component.

• Render props can make components more reusable and flexible.

• Example: } />

Data sharing techniques involve methods and technologies used to share data between different systems or applications.

• APIs (Application Programming Interfaces) allow systems to communicate and share data

• Data integration tools enable the consolidation and sharing of data from multiple sources

• Data warehouses and data lakes provide centralized repositories for data sharing

• Message queues and publish-subscribe systems facilitate asynchronous data sharing

• Data serialization formats ...read more

Spark architecture is a distributed computing framework that allows processing of large datasets in parallel across a cluster of computers.

• Spark architecture consists of a driver program, a cluster manager, and worker nodes.

• The driver program runs the main function and creates a SparkContext object.

• The cluster manager allocates resources and schedules tasks on worker nodes.

• Worker nodes execute tasks and return results to the driver program.

• Spark architecture supports various ...read more

Java8 stream program to demonstrate filtering and mapping operations.

• Use stream() method to convert a collection into a stream.

• Use filter() method to apply a condition for filtering elements.

• Use map() method to transform each element into another form.

Redux Toolkit is a set of tools and best practices for managing state in React applications.

• Redux Toolkit simplifies the process of writing Redux code by providing a set of tools like createSlice, createAsyncThunk, and configureStore.

• It helps reduce boilerplate code and makes it easier to set up a Redux store.

• Redux Toolkit also includes utilities like createSelector for creating memoized selectors.

• Example: const counterSlice = createSlice({ name: 'counter', initialState: 0, r...read more