20+ Nirman Consultants Interview Questions and Answers

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.

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)}});

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

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

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.

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

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

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.

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.

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 connection object inside a class, the object is passed as a ...read more

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

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

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.

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

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

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

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

Built a react feature

• Identify the specific feature to be built

• Design the component hierarchy and state management

• Implement the feature using React components and hooks

• Test the feature for functionality and user experience

• Refactor and optimize the code for performance

Yes, telecalling involves making phone calls to potential clients or customers to promote products or services.

• Telecalling involves making outbound calls to potential customers or clients.

• The goal of telecalling is to promote products or services, generate leads, or set up appointments.

• Telecallers need to have good communication skills, be persuasive, and have a clear understanding of the product or service they are promoting.

VXLAN fabric is a virtualized network overlay technology that enables the extension of Layer 2 networks over Layer 3 networks.

• VXLAN stands for Virtual Extensible LAN

• It uses a 24-bit VNID (VXLAN Network Identifier) to uniquely identify each virtual network

• VXLAN encapsulates Layer 2 Ethernet frames within Layer 3 UDP packets for transmission across the network

• Underlay network provides the physical connectivity between VXLAN tunnel endpoints (VTEPs)

• Overlay network is the logical...read more

Yes, I plan to pursue a Master's degree after graduation.

• I am currently researching different programs and universities for my post-graduation studies.

• I plan to specialize in a specific field related to my undergraduate degree.

• I am preparing for standardized tests required for admission, such as the GRE or GMAT.

• I am also working on my personal statement and gathering letters of recommendation.

• I am considering potential research topics or thesis ideas for my Master's program.