Airtel Payments Bank Software Engineer Interview Questions and Answers

Need more context. What needs to be done with the large rectangle?

• What are the dimensions of the rectangle?

• Is it a 2D or 3D object?

• What is the context of the problem?

• Are there any constraints or limitations?

• What tools or programming languages can be used?

Derive a formula to determine how many smaller rectangles fit into a bigger rectangle given their dimensions.

• Calculate the number of times the smaller rectangle can fit into the bigger rectangle horizontally and vertically

• Divide the width of the bigger rectangle by the width of the smaller rectangle to get the horizontal count

• Divide the height of the bigger rectangle by the height of the smaller rectangle to get the ve...read more

At least 4 points are required to draw a rectangle.

• A rectangle has 4 sides and 4 corners, so at least 4 points are needed to define those corners.

• The points must be arranged in a specific order to form a closed shape with 4 sides.

• Additional points can be used to add details or modify the shape of the rectangle.

• The number of points required may vary depending on the software or tool used to draw the rectangle.

Answering how to calculate new coordinates of a scaled rectangle and providing a program for it.

• To calculate new coordinates, multiply the original coordinates by the scaling factor

• Scaling factor can be calculated by dividing the new length/breadth by the original length/breadth

• Program can take input of original coordinates, scaling factor, and output new coordinates

• Example: Original coordinates: (0,0), (0,5), (5,5), (...read more

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)}});

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 Serv

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

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

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.

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.

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

Dependency injection is a design pattern that allows objects to receive dependencies rather than creating them internally.

• It helps to decouple the code and makes it more testable and maintainable.

• It allows for easier swapping of dependencies without changing the code.

• There are three types of dependency injection: constructor injection, setter injection, and interface injection.

• Example: Instead of creating a database co...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 cook

CORS can be overcome by configuring the server to allow cross-origin requests.

• Configure the server to include the Access-Control-Allow-Origin header

• Use JSONP (JSON with Padding) to bypass CORS restrictions

• Use a proxy server to make the request on behalf of the client

• Use a browser extension to disable CORS restrictions during development

• Use a server-side proxy to forward requests to the target server

Deadlock is a situation where two or more processes are unable to proceed because each is waiting for the other to release a resource.

• Deadlock occurs when two or more processes are stuck in a circular wait, where each process is waiting for a resource held by another process.

• Four necessary conditions for deadlock are mutual exclusion, hold and wait, no preemption, and circular wait.

• Example: Process A holds resource X a...read more

I have experience with various technologies including Java, Python, HTML/CSS, JavaScript, and SQL.

• Java

• Python

• HTML/CSS

• JavaScript

• SQL

I am looking for a change to explore new opportunities and challenges. My notice period is 30 days.

• Seeking new opportunities and challenges

• Want to learn and grow in a different environment

• Exploring better career prospects

• Seeking a company with a better work-life balance

• Notice period is 30 days