30+ Netradyne Technology Interview Questions and Answers

Program to get employee list with salary > 50k and grade above A using Java 8 stream

• Create a list of employees with their salary and grade

• Use Java 8 stream to filter employees with salary > 50k and grade above A

• Return the filtered list of employees

Security authentication implementation and delegation explained.

• Security authentication is the process of verifying the identity of a user or system.

• It involves the use of passwords, biometrics, tokens, or other methods to authenticate users.

• Delegation is the process of granting a user or system the authority to perform certain actions on behalf of another user or system.

• Examples of delegation include granting a user access to a file or folder, or allowing a system to access ...read more

Implemented microservices using Docker and Kubernetes. Used Prometheus and Grafana for API monitoring.

• Implemented microservices architecture using Docker and Kubernetes

• Used Prometheus and Grafana for monitoring API performance and availability

• Configured alerts and dashboards in Grafana for real-time monitoring

• Implemented distributed tracing using Jaeger for end-to-end visibility

• Used Istio for service mesh and traffic management

• Implemented circuit breaker pattern using Hystrix...read more

I configured API Gateway using AWS Console and created APIs for each microservice.

• Created a REST API in API Gateway

• Configured each microservice as a resource in the API

• Created methods for each resource and integrated with the microservice

• Configured authorization and throttling settings

• Deployed the API to a stage for testing and production

• Used AWS SDKs or CLI to automate the process

To fix code issues post migrations, identify the root cause and apply appropriate fixes.

• Identify the root cause of the issue

• Check for any compatibility issues with the new environment

• Apply appropriate fixes such as code changes or configuration updates

• Test the fixes thoroughly before deploying to production

• Document the issue and the fix for future reference

Flatten array of objects to map with minimum price for each model

• Iterate through the array and create a map with model as key and minimum price as value

• If model already exists in map, update the value with minimum price

• Return the map as the output

I followed various approaches like code optimization, database indexing, caching, and load balancing.

• Identified and optimized slow database queries

• Reduced network latency by implementing caching mechanisms

• Implemented load balancing to distribute traffic evenly

• Reduced code complexity and optimized algorithms

• Used profiling tools to identify performance bottlenecks

Use SQL query with OFFSET and LIMIT to find 10 max salaries from employee table in PostgreSQL.

• Use ORDER BY clause to sort salaries in descending order

• Use LIMIT 10 to get only the top 10 salaries

• Use OFFSET 0 to start from the beginning of the sorted list

Hash Map in Java 8 has introduced several new features and improvements.

• Hash Map now uses a balanced tree instead of a linked list for collision resolution when the number of elements in a bucket exceeds a certain threshold.

• The new method 'computeIfAbsent' has been added to Hash Map which allows for a more concise way of adding new key-value pairs.

• The 'forEach' method has been added to Hash Map which allows for iterating over all key-value pairs in the map.

• The 'merge' method ...read more

Find 4 non-repeating characters in the given string.

• Create a hashmap to store character frequencies

• Iterate through the string and count the occurrences of each character

• Return the first 4 characters with frequency 1 as non-repeating characters

Use a thread pool executor to execute 3 methods in parallel and wait for all 3 to complete.

• Create a thread pool executor with a fixed number of threads.

• Submit the 3 methods as tasks to the executor using the `submit()` method.

• Use the `invokeAll()` method to wait for all tasks to complete.

• Handle any exceptions thrown by the tasks.

• Example: ThreadPoolExecutor executor = new ThreadPoolExecutor(3, 3, 0L, TimeUnit.MILLISECONDS, new LinkedBlockingQueue<>());

• Example: Future task1 = e...read more

The @async annotation is used to make an API asynchronous.

• Add the @async annotation to the method declaration

• Use CompletableFuture or a similar mechanism to handle the asynchronous execution

• Ensure the API returns a CompletableFuture or a similar asynchronous result

Durable orchestration in Azure Function allows for long-running, stateful workflows to be executed efficiently.

• Durable orchestration enables developers to write stateful functions that can be paused and resumed at any point.

• It provides features like checkpointing, error handling, and timeouts to ensure reliability.

• By using durable functions, complex workflows can be easily implemented without the need for external orchestration services.

• Example: A durable function can be used...read more

Program to get header values xyz from a web api

• Use a programming language that supports making HTTP requests, such as Python or JavaScript

• Make a request to the web API and retrieve the response headers

• Parse the headers to extract the value of the 'xyz' header

Spark is a fast and general-purpose cluster computing system, while Hadoop is a distributed processing framework.

• Spark is designed for in-memory processing, while Hadoop is disk-based.

• Spark provides real-time processing capabilities, while Hadoop is primarily used for batch processing.

• Spark has a more flexible and expressive programming model compared to Hadoop's MapReduce.

• Spark can be used with various data sources like HDFS, HBase, and more, while Hadoop is typically used w...read more

Different authentication methods in REST API

• Basic authentication - uses a username and password for authentication

• Token-based authentication - uses tokens generated by the server for authentication

• OAuth - allows third-party services to exchange user's data without exposing passwords

• API keys - unique identifier used to authenticate requests to the API

IKM stands for Interactive Knowledge Modules. There are two types: Standard and Customized.

• Standard IKMs are pre-built modules that cover a wide range of topics

• Customized IKMs are tailored to specific needs and can include company-specific information

• Examples of customization include adding company branding, modifying content to fit specific workflows, and incorporating company policies and procedures

• Customized IKMs can also include interactive elements such as quizzes and si...read more

Higher order functions in JavaScript are functions that can take other functions as arguments or return functions as output.

• Higher order functions can be used to create more flexible and reusable code.

• Examples include functions like map, filter, and reduce in JavaScript.

• They allow for functions to be passed as parameters, making code more concise and readable.

Python class lifestyle methods are special methods that are automatically called at different points in the life cycle of a class object.

• Constructor method (__init__): Called when a new instance of the class is created.

• Destructor method (__del__): Called when an instance of the class is about to be destroyed.

• String representation method (__str__): Called when the object needs to be represented as a string.

• Getter and setter methods: Used to get and set the values of class attr...read more

To find the 10th highest salary for a given employee class.

• Sort the salaries in descending order for the specific employee class.

• Skip duplicates and find the 10th unique salary.

• Return the 10th salary as the 10th Max. Salary.

React is a JavaScript library for building user interfaces. Virtual DOM is a lightweight copy of the actual DOM.

• React allows developers to create reusable UI components

• Virtual DOM is a faster way to update the UI compared to traditional DOM manipulation

• React uses the virtual DOM to efficiently update the actual DOM

• Virtual DOM is a tree-like structure that represents the UI components

• React compares the previous and current virtual DOM to determine the changes and updates the a...read more

Hash map is a data structure that maps keys to values using a hash function.

• Hash map uses a hash function to compute an index into an array of buckets or slots.

• The key is hashed and the resulting hash code is used to locate the value in the hash table.

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

• Hash maps have O(1) average time complexity for insertion, deletion, and retrieval.

• Examples of hash maps include...read more

Lazy loading of beans in Spring Boot allows beans to be loaded only when they are needed, improving performance.

• Lazy loading can be achieved by using @Lazy annotation on bean definitions

• Lazy loading can also be configured in application.properties using spring.main.lazy-initialization=true

• Lazy loading is useful for optimizing application startup time and memory usage

Create a component to fetch and display data from an API

• Use a library like Axios or Fetch to make API requests

• Parse the JSON data received from the API

• Display the data in a user-friendly format on the front end

Custom hook to fetch data in React

• Create a custom hook using the 'useEffect' and 'useState' hooks

• Use 'fetch' or any other method to fetch data from an API

• Return the fetched data from the custom hook

Azure function is a serverless compute service that allows you to run code without managing infrastructure.

• Azure function is event-driven and can be triggered by various events like HTTP requests, timers, or messages from other Azure services.

• It supports multiple programming languages like C#, Java, Python, and Node.js.

• Azure functions can be used for tasks like data processing, file manipulation, or integrating with other services.

• They are cost-effective as you only pay for t...read more

BDD framework is a behavior-driven development framework used for testing software applications.

• BDD focuses on the behavior of the system from the end user's perspective.

• It uses natural language specifications to define the expected behavior of the system.

• BDD frameworks like Cucumber and SpecFlow help in creating executable specifications.

• BDD promotes collaboration between developers, testers, and business stakeholders.

splice is used to add/remove elements from an array, while slice is used to create a new array from a portion of an existing array.

• splice modifies the original array, while slice does not

• splice can add elements to an array at a specific index

• slice can extract a portion of an array without modifying the original array

• splice returns the removed elements, while slice returns the extracted elements

NF in SQL refers to Normal Form which is used to eliminate redundancy in database design. ACID concepts ensure data integrity in transactions.

• NF in SQL stands for Normal Form and is used to organize data in a database to eliminate redundancy and dependency.

• There are different levels of NF such as 1NF, 2NF, 3NF, and BCNF, each with specific rules to follow.

• ACID concepts (Atomicity, Consistency, Isolation, Durability) ensure data integrity in database transactions by guaranteei...read more

Using callable and future in Java for asynchronous tasks

• Use Callable interface to represent a task that returns a result

• Use Future interface to represent the result of an asynchronous computation

• Example: Callable task = () -> { return 5; }

• Example: Future future = executor.submit(task);

Spark Architecture is a distributed computing framework that provides high-speed data processing and analytics.

• Spark Architecture is based on a master/worker model.

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

• The cluster manager allocates resources and schedules tasks.

• The driver program defines the computation and coordinates the execution.

• Worker nodes execute the tasks and store data in memory or disk.

• Spark Architecture supports various data sources a...read more

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

• Inheritance: Allows a class to inherit properties and behavior from another class. Example: class Dog extends Animal.

• Encapsulation: Bundles data and methods that operate on the data into a single unit. Example: private variables with public methods.

• Polymorphism: Allows objects of different classes to be treated as objects of a common superclass. Example: Animal class with different subclasses like ...read more

Micro services are used for breaking down large applications into smaller, independent services that can be developed, deployed, and scaled independently.

• Scalability: Micro services allow for easier scaling of individual components without affecting the entire system.

• Flexibility: Each micro service can be developed using different technologies, languages, and frameworks.

• Resilience: Failure in one micro service does not bring down the entire system.

• Ease of deployment: Micro se...read more