200+ REGEN INFRASTRUCTURE AND SERVICES Interview Questions and Answers

Spark architecture is a distributed computing framework that consists of a cluster manager and worker nodes.

• Consists of a cluster manager (e.g. Spark Standalone, YARN, Mesos) for resource management

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

• Supports various programming languages like Scala, Java, Python, and SQL

• Uses Resilient Distributed Datasets (RDDs) for fault-tolerant distributed data processing

My framework is a data-driven framework using Selenium WebDriver and TestNG for automated testing.

• Data-driven approach for reusability and maintainability

• Integration with Selenium WebDriver for browser automation

• Utilizes TestNG for test case management and reporting

High level of automation views refers to the belief that automation is the key to efficient and effective testing.

• Automation should be used to increase efficiency and reduce manual effort

• Automation should be used to increase test coverage and accuracy

• Automation should be used to reduce the time required for testing

• Automation should be used to increase the reliability of testing

• Automation should be used to increase the speed of feedback and reduce the time to market

DBAs are responsible for managing and maintaining databases on a day-to-day basis.

• Performing regular backups and restores of databases

• Monitoring database performance and optimizing queries

• Troubleshooting and resolving database issues

• Implementing security measures to protect data

• Collaborating with developers to design and implement database solutions

I am a detail-oriented Quality Analyst with a strong background in analyzing data and identifying areas for improvement.

• Experienced in conducting quality assurance tests and implementing quality control procedures

• Skilled in identifying defects, tracking issues, and providing solutions

• Proficient in using testing tools and software to ensure product quality

• Strong communication skills to collaborate with cross-functional teams and stakeholders

Hooks in React are functions that let you use state and other React features in functional components.

• Hooks were introduced in React 16.8 to allow functional components to have state and lifecycle methods.

• useState() is a hook that allows you to add state to functional components.

• useEffect() is a hook that lets you perform side effects in functional components.

• Custom hooks are reusable functions that can contain stateful logic and be shared across components.

Sample React code for a timer component

• Use useState to store the timer value

• Use useEffect to update the timer every second

• Display the timer value in the component's render method

Runnable and Callable are interfaces in Java used for implementing multithreading.

• Runnable interface is used for creating a thread and implementing the run() method.

• Callable interface is used for creating a thread and returning a result using the call() method.

• Runnable interface is simpler to use than Callable interface.

• Callable interface can throw checked exceptions while Runnable interface cannot.

Hive metastore is a central repository that stores metadata for Hive tables and partitions.

• Hive metastore stores metadata such as table schema, location, and partition information.

• It allows multiple Hive sessions to access and share metadata.

• Metastore can be implemented using different databases like MySQL, PostgreSQL, or Derby.

• It is crucial for query optimization and data retrieval in Hive.

Oops concepts are fundamental to object-oriented programming and include inheritance, polymorphism, encapsulation, and abstraction.

• Inheritance allows a class to inherit properties and methods from a parent class.

• Polymorphism allows objects to take on multiple forms and behave differently depending on the context.

• Encapsulation hides the implementation details of a class and only exposes necessary information.

• Abstraction focuses on the essential features of an object and hides ...read more

Singleton is a design pattern in Java where a class is restricted to have only one instance.

• Singleton pattern ensures that a class has only one instance and provides a global point of access to it.

• It is commonly used in scenarios where a single instance of a class is required to control actions throughout a system.

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

Ansible and Terraform are tools used for automation and infrastructure management.

• Ansible is used for configuration management and automation of IT infrastructure.

• Terraform is used for infrastructure as code and provisioning of resources.

• Both tools can be used together to manage infrastructure and automate deployment.

• Ansible can be used to configure servers and deploy applications, while Terraform can be used to provision the necessary infrastructure.

• For example, Ansible can ...read more

MRO in Python refers to Method Resolution Order, which determines the order in which methods are called in a class hierarchy.

• MRO is important in multiple inheritance in Python

• It is determined by the C3 linearization algorithm

• You can view the MRO of a class using the __mro__ attribute

• MRO can be affected by method overriding and super() calls

Global exception handling is a mechanism to handle exceptions that occur throughout an application.

• Global exception handling allows for centralized handling of exceptions in an application.

• It helps in maintaining a consistent error handling strategy across the application.

• By using global exception handling, developers can catch and handle exceptions at a higher level in the application.

• Examples include using a global exception handler to log errors, display user-friendly erro...read more

An interface is a contract between two systems or components that defines the methods and properties that one system can use from the other.

• An interface defines a set of methods and properties that a class must implement

• Interfaces provide a way to achieve polymorphism in object-oriented programming

• Interfaces are used to define contracts between different parts of a system

• Interfaces can be used to define common functionality that can be shared across multiple classes

• Examples o...read more

Appium is an open-source tool for automating mobile, web, and hybrid applications on iOS and Android platforms.

• Appium supports automation of native, hybrid, and mobile web applications.

• It uses the WebDriver protocol to drive iOS and Android apps.

• Appium can run tests on simulators/emulators or real devices.

• It supports multiple programming languages like Java, Python, Ruby, etc.

• Appium is widely used for mobile test automation in the industry.

Custom middleware in .NET allows for custom logic to be executed before or after an HTTP request is processed.

• Create a class that implements the IMiddleware interface

• Override the InvokeAsync method to add custom logic

• Register the middleware in the Startup class using the UseMiddleware extension method

Trade life cycle refers to the stages involved in a trade from initiation to settlement.

• Trade initiation: Trade is proposed and agreed upon by parties involved.

• Trade execution: Trade is executed on the agreed terms.

• Trade confirmation: Parties confirm the details of the trade.

• Trade settlement: Payment and transfer of securities are completed.

• Trade reconciliation: Ensuring all details match between parties involved.

• Trade reporting: Reporting the trade to relevant authorities.

• Tr...read more

Types of joins in SQL are Inner Join, Left Join, Right Join, and Full Join.

• Inner Join: Returns rows when there is a match in both tables.

• Left Join: Returns all rows from the left table and the matched rows from the right table.

• Right Join: Returns all rows from the right table and the matched rows from the left table.

• Full Join: Returns rows when there is a match in either table.

The average Node.js API design involves creating modular and scalable code, using RESTful principles, and implementing error handling and authentication.

• Use modular code structure to separate concerns and improve maintainability

• Follow RESTful principles for designing API endpoints and handling HTTP methods

• Implement error handling to provide meaningful error messages and handle exceptions

• Include authentication mechanisms like JWT or OAuth for secure access to API endpoints

Agile ways of working refer to a flexible and iterative approach to project management.

• Agile emphasizes collaboration, adaptability, and continuous improvement.

• It involves breaking down projects into smaller, manageable tasks called sprints.

• Regular meetings, such as daily stand-ups and sprint reviews, are held to track progress and make adjustments.

• Agile also prioritizes customer satisfaction and delivering value early and often.

• Examples of Agile methodologies include Scrum, ...read more

SOLID principles are a set of five design principles in object-oriented programming to make software more maintainable, flexible, and scalable.

• S - Single Responsibility Principle: A class should have only one reason to change.

• O - Open/Closed Principle: Software entities should be open for extension but closed for modification.

• L - Liskov Substitution Principle: Objects of a superclass should be replaceable with objects of its subclasses without affecting the functionality.

• I - ...read more

kubectl is a command line tool for interacting with Kubernetes clusters.

• Used to deploy applications, inspect and manage cluster resources, and view logs.

• Can be used to create, delete, and update resources in a Kubernetes cluster.

• Allows for scaling deployments, rolling updates, and debugging applications.

• Provides access to cluster information such as nodes, pods, services, and namespaces.

Scala Object is a singleton instance of a class that can be used to hold utility methods or constants.

• Scala Object is similar to Java static class

• It can hold utility methods or constants

• It is a singleton instance of a class

• It is used to encapsulate stateless functionality

• Example: object MathUtils { def add(a: Int, b: Int) = a + b }

• Example: val result = MathUtils.add(2, 3)

CAB stands for Change Advisory Board, a group responsible for reviewing and approving changes to IT systems.

• CAB is a group of stakeholders who evaluate proposed changes to IT systems.

• They assess the potential impact of changes and determine whether they should be approved or rejected.

• CAB members may include representatives from IT, business, and other areas of the organization.

• CAB meetings are typically held regularly to review change requests and make decisions.

• Examples of c...read more

MVC is a design pattern used in .NET development, while .NET lifecycle refers to the stages of a .NET application's execution.

• MVC is a design pattern that separates an application into three main components: Model, View, and Controller.

• .NET lifecycle refers to the stages of a .NET application's execution, including initialization, execution, and termination.

• MVC helps in achieving separation of concerns and making the code more maintainable.

• Understanding the .NET lifecycle is ...read more

Stored procedures are precompiled SQL queries stored in the database, while functions are reusable code blocks that return a value.

• Stored procedures are used for performing specific tasks or operations on the database.

• Functions are used to encapsulate logic and can be called within SQL queries or other functions.

• Stored procedures can have input and output parameters, while functions always return a value.

• Stored procedures can contain DML and DDL statements, while functions ar...read more

NgOnInit is a lifecycle hook in Angular that is called after the component has been initialized, while the constructor is a TypeScript feature used to initialize class properties.

• NgOnInit is specific to Angular components, while constructor is a general TypeScript feature.

• NgOnInit is used for initialization logic that relies on Angular's view and input bindings being initialized, while constructor is used for basic initialization of class properties.

• NgOnInit is called after A...read more

A dashboard is a visual representation of data that provides a quick overview of key performance indicators and metrics.

• Dashboards typically consist of charts, graphs, and tables to display data in a concise and easy-to-understand format.

• They are used to track progress, identify trends, and make informed decisions based on real-time data.

• Examples of dashboards include project status dashboards, financial performance dashboards, and sales performance dashboards.

SSL pinning is a security measure used to prevent man-in-the-middle attacks by associating a specific SSL certificate with a particular app.

• SSL pinning involves hardcoding the expected SSL certificate or public key within the mobile app.

• This helps verify the server's identity and prevent attackers from intercepting and decrypting communication.

• SSL pinning can be implemented using libraries like TrustKit or manually by extracting the certificate and adding it to the app's code...read more

Sort array of strings with a given value

• Use Arrays.sort() method with a custom Comparator to sort the array based on the given value

• Handle cases where the given value is not present in the array

• Example: Sort array ['apple', 'banana', 'orange', 'grape'] with 'banana' as the given value

Java 8 Default Method allows interfaces to have method implementations.

• Introduced in Java 8 to provide backward compatibility for interfaces

• Can have method implementations in interfaces using the 'default' keyword

• Used to add new methods to interfaces without breaking existing implementations

Finding duplicate values in an array of strings

• Iterate through the array and store each element in a hash set

• If an element is already in the hash set, it is a duplicate

• Return the duplicate values found

Generators in JavaScript are functions that can be paused and resumed, allowing for asynchronous programming.

• Generators are defined using function* syntax.

• They use the yield keyword to pause execution and return a value.

• Generators can be iterated over using a for...of loop.

• They are commonly used for asynchronous operations and managing state.

Redux is a predictable state container for JavaScript apps.

• Redux is a state management library commonly used with React.

• It follows a unidirectional data flow pattern.

• Actions are dispatched to update the state through reducers.

• State changes are handled immutably.

• Selectors can be used to access specific parts of the state.

• Middleware can be used for side effects like async operations.

• Example: Dispatching an action to add an item to a shopping cart.

My framework is a combination of Selenium WebDriver for automated testing and TestNG for test management.

• Utilizes Selenium WebDriver for interacting with web elements

• Uses TestNG for test case management and execution

• Employs Page Object Model design pattern for better code organization

OOPS concepts of Java

• Encapsulation - binding data and methods together

• Inheritance - creating new classes from existing ones

• Polymorphism - ability of objects to take many forms

• Abstraction - hiding implementation details

• Interfaces - defining a set of methods that a class must implement

• Classes - blueprint for creating objects

Oops concepts in Java are fundamental principles of object-oriented programming such as inheritance, polymorphism, encapsulation, and abstraction.

• Inheritance: Allows a class to inherit properties and behavior from another class.

• Polymorphism: Ability of an object to take on many forms.

• Encapsulation: Bundling data and methods that operate on the data into a single unit.

• Abstraction: Hiding the implementation details and showing only the necessary features of an object.

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

• Inheritance: Allows a class to inherit properties and behavior from another class.

• Encapsulation: Bundling data and methods that operate on the data into a single unit.

• Polymorphism: Ability to present the same interface for different data types.

• Abstraction: Hiding the implementation details and showing only the necessary features.

Decorators in Python are functions that modify the behavior of other functions or methods.

• Decorators are defined using the @decorator_name syntax before a function definition.

• They can be used to add functionality to existing functions without modifying their code.

• Decorators can be used for logging, authentication, caching, and more.

• Example: @staticmethod decorator in Python is used to define a method that doesn't receive an implicit first argument.

Routing in Angular allows for navigation between different components and views within an application.

• Angular's router module provides a way to define routes and their corresponding components.

• Routes can be configured with path, component, and other properties.

• RouterOutlet is used to display the component associated with the current route.

• RouterLink is used to navigate to different routes.

• Child routes can be defined to create nested navigation.

• Guards can be used to control ac...read more

Python project overview

• Describe the purpose and goals of the project

• Explain the technologies and tools used in the project

• Discuss the project's architecture and design

• Highlight any challenges faced and how they were overcome

Dispose is used to release unmanaged resources immediately, while Finalize is used for cleanup operations before an object is destroyed by the garbage collector.

• Dispose is called explicitly by the developer, while Finalize is called by the garbage collector.

• Dispose should be implemented in classes that directly interact with unmanaged resources.

• Finalize should be implemented in classes that need to release resources before being garbage collected.

• Example: Implement IDisposabl...read more

Model binder in MVC is used to map data from HTTP requests to action method parameters in controllers.

• Model binder maps form data, query string parameters, and route data to action method parameters in MVC controllers.

• It helps in simplifying the process of extracting data from HTTP requests.

• Model binder can be customized by creating custom model binders to handle complex data binding scenarios.

zone.js is a library for managing asynchronous operations in Angular applications.

• zone.js helps in tracking asynchronous operations and their execution context in Angular applications.

• It provides hooks for intercepting asynchronous tasks like setTimeout, setInterval, and promises.

• zone.js can be used for profiling, debugging, and error handling in Angular applications.

A class is a blueprint or template for creating objects, while an object is an instance of a class.

• A class defines the properties and behaviors of objects, while an object is a specific instance of a class.

• Classes can be used to create multiple objects with similar characteristics.

• Objects have state (attributes) and behavior (methods) defined by the class.

• Example: Class 'Car' defines properties like 'color' and 'model', while an object 'myCar' can have specific values for the...read more

SQL queries for Senior Quality Analyst position

• Use SELECT statement to retrieve data from database

• Use WHERE clause to filter data based on specific conditions

• Use JOIN clause to combine data from multiple tables

• Use GROUP BY clause to group data based on specific columns

• Use ORDER BY clause to sort data in ascending or descending order