40+ Interview Questions and Answers

REST API is a web service that uses HTTP methods to interact with resources. GET, PUT, POST, DELETE, MERGE, PATCH are different methods.

• REST API is a stateless architecture that uses HTTP methods to interact with resources.

• GET method is used to retrieve data from a server.

• PUT method is used to update an existing resource on the server.

• POST method is used to create a new resource on the server.

• DELETE method is used to delete a resource from the server.

• MERGE method is used to u...read more

Caching can speed up request response. Popular caches include Redis, Memcached, and browser caching.

• Caching stores frequently accessed data in memory for faster retrieval

• Browser caching stores static assets like images and CSS files

• Redis and Memcached are popular in-memory caching solutions for web applications

• Cache invalidation is important to ensure data consistency

JWT token is used to secure endpoints in REST APIs by providing authentication and authorization.

• JWT stands for JSON Web Token

• It is a compact, URL-safe means of representing claims to be transferred between two parties

• It is used for authentication and authorization

• It contains three parts: header, payload, and signature

• The header contains the algorithm used to sign the token

• The payload contains the claims or information about the user

• The signature is used to verify the authent...read more

Angular code to fetch and display JSON response in tabular format.

• Use HttpClient module to make an HTTP GET request to the given URL.

• Subscribe to the response and extract the JSON data.

• Create an Angular component to display the data in a tabular format using HTML and CSS.

Answers to questions related to vacuum technology and design.

• Vacuum is a space devoid of matter. Outgassing is the release of trapped gases from a material in a vacuum.

• Considerations for designing a vacuum chamber include material selection, sealing methods, and pumping speed.

• A virtual leak is a false indication of a leak caused by gas trapped in a chamber or system.

• Virtual leak and outgassing are not the same.

• Venting is the process of releasing gas from a chamber or system t...read more

Perl DBI module is used to connect to databases and fetch data from tables.

• Use DBI module to connect to database using appropriate driver, username, password, and database name

• Prepare and execute SQL queries to fetch data from tables using DBI module

• Use fetchrow_array() or fetchrow_hashref() methods to retrieve data from query results

Iterate through the string from end to beginning and append each character to a new string.

• Create an empty string to store the reversed string.

• Iterate through the original string from end to beginning.

• Append each character to the new string.

• Return the reversed string.

Virtual DOM is a lightweight copy of the real DOM that allows for efficient updates without directly manipulating the actual DOM.

• Virtual DOM is a concept used in frameworks like React to improve performance by minimizing direct DOM manipulation.

• Changes are first made to the virtual DOM, which is then compared to the real DOM to identify the minimal updates needed.

• This process reduces the number of actual DOM manipulations, leading to faster rendering and improved performance....read more

UL 94 is a flammability standard for plastic materials. SS304 and SS316 are different grades of stainless steel. Various materials are used in vacuum chambers.

• UL 94 is a standard used to measure the flammability of plastic materials.

• SS304 and SS316 are both grades of stainless steel, but SS316 has higher corrosion resistance and strength.

• Materials used in vacuum chambers include stainless steel, aluminum, and glass.

• The choice of material for a vacuum chamber depends on factor...read more

Facing real-time KPI issues related to data accuracy and system performance

• Data inconsistency leading to inaccurate KPI calculations

• System lag affecting real-time updates of KPI metrics

• Difficulty in integrating data from multiple sources for comprehensive KPI analysis

Acceptance testing can be performed by creating test cases based on user requirements and executing them to ensure the system meets the acceptance criteria.

• Create test cases based on user requirements

• Execute test cases to ensure the system meets acceptance criteria

• Automate acceptance testing using tools like Selenium or Cucumber

• Involve stakeholders in the acceptance testing process to ensure their needs are met

Closure is a function that has access to variables in its outer scope, even after the outer function has returned.

• A closure is created when a function returns another function that references variables from the outer function's scope.

• Closures are commonly used in JavaScript to create private variables and functions.

• The Technical Lead's role in relation to closures may involve optimizing code that uses closures or helping team members understand how to use closures effectively...read more

Create a Bash script to automate repeated tasks for Linux admin in Azure cloud

• Use Azure CLI commands to interact with Azure resources

• Utilize loops and conditional statements for automation

• Implement error handling and logging for script reliability

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

• 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 func...read more

Developed a project management tool using Java Swing architecture.

• Used MVC design pattern to separate data, presentation, and user interaction.

• Implemented various Swing components like JTable, JTree, and JDialog for user interface.

• Utilized event handling to capture user actions and update the model accordingly.

Rest APIs are a set of rules and protocols that allow different software applications to communicate with each other over the internet.

• Rest APIs use HTTP methods like GET, POST, PUT, DELETE to perform actions on resources.

• They typically return data in JSON or XML format.

• Rest APIs are stateless, meaning each request from a client to the server must contain all the information necessary to understand the request.

JWT token is a popular method for securing REST APIs by providing authentication and authorization.

• Generate JWT token upon successful authentication

• Include token in Authorization header for subsequent API requests

• Verify token signature to ensure authenticity

• Set token expiration time to enhance security

Angular is a JavaScript framework for building web applications. It has a component-based architecture and a well-defined lifecycle.

• Angular lifecycle consists of several phases that a component goes through from creation to destruction.

• The main phases are: ngOnChanges, ngOnInit, ngDoCheck, ngAfterContentInit, ngAfterContentChecked, ngAfterViewInit, ngAfterViewChecked, ngOnDestroy.

• Each phase has a specific purpose and can be used to perform certain actions or manipulate the co...read more

Drupal is a free and open-source content management system (CMS) written in PHP.

• Drupal is used to create and manage websites, blogs, and online stores.

• It offers a wide range of features and modules for customization.

• Drupal has a large community of developers and users who contribute to its development and support.

• Some popular websites built on Drupal include The Economist, NBC, and The White House.

• Drupal is known for its flexibility, scalability, and security.

• It is used by bu...read more

As a tech lead, I have conducted various scrum ceremonies including daily stand-ups, sprint planning, sprint review, and retrospective meetings.

• Conducted daily stand-up meetings to discuss progress and plan for the day

• Facilitated sprint planning meetings to set goals and prioritize tasks for the upcoming sprint

• Organized sprint review meetings to showcase completed work and gather feedback from stakeholders

• Led retrospective meetings to reflect on the previous sprint and identi...read more

Notice period is the time period between an employee's resignation and their last day of work.

• It is a common practice in most companies to have a notice period

• The duration of the notice period varies from company to company and can range from a few weeks to a few months

• During the notice period, the employee is expected to complete any pending work and handover their responsibilities to their successor

• The notice period is also a time for the company to find a replacement for t...read more

My expected CTC is based on my experience, skills, and the market rate for the position.

• Consider my years of experience in the industry

• Factor in my technical skills and certifications

• Research the current market rate for Technical Lead positions in the industry

Event loop in JavaScript manages asynchronous operations by executing callback functions in a queue.

• Event loop is responsible for handling asynchronous operations in JavaScript.

• It continuously checks the call stack and the callback queue to see if there are any functions that need to be executed.

• If the call stack is empty, the event loop will take a function from the callback queue and push it onto the call stack for execution.

• Example: setTimeout() function in JavaScript uses...read more

Polyfill is a piece of code that provides the functionality that is not natively available in a browser.

• Polyfill for the call method in JavaScript is used to provide support for older browsers that do not natively support the call method.

• It is typically implemented using the Function.prototype.call method.

• Example: Function.prototype.call = Function.prototype.call || function() { // polyfill code here }

Azure Active Directory (AAD) provides identity and access management services for Azure resources.

• AAD is used to manage user identities and control access to Azure resources

• It provides single sign-on (SSO) capabilities for users to access multiple applications with one set of credentials

• AAD integrates with various Azure services like Azure Virtual Machines, Azure App Service, Azure SQL Database, etc.

• It offers features like Multi-Factor Authentication (MFA), Conditional Access...read more

A program to calculate the date difference between two given dates.

• Use a date library or built-in functions to calculate the difference in days, months, or years.

• Consider leap years and different month lengths when calculating the difference.

• Handle edge cases like dates in different years or dates with different time zones.

Project management methodologies are frameworks used to plan, execute, and manage projects efficiently.

• Common project management methodologies include Agile, Waterfall, Scrum, and Kanban.

• Agile focuses on iterative development and flexibility.

• Waterfall follows a linear sequential approach.

• Scrum involves small, cross-functional teams working in sprints.

• Kanban visualizes work on a board with columns representing different stages.

Project development involves various phases such as planning, design, implementation, testing, and deployment.

• Planning phase involves defining project scope, goals, and requirements.

• Design phase focuses on creating a detailed blueprint of the project.

• Implementation phase involves coding and building the project.

• Testing phase is where the project is tested for bugs and errors.

• Deployment phase is when the project is released to users.

• Each phase is crucial for the success of the...read more

4G attach procedures involve multiple messages exchanged between the UE and the network.

• UE sends attach request to the network

• Network validates the request and assigns temporary identities to the UE

• Network sends attach accept message to UE

• UE sends attach complete message to network to complete the attach procedure

A coroutine is a concurrency design pattern that allows multiple entry points for suspending and resuming execution.

• Coroutines are used to perform asynchronous operations without blocking the main thread.

• They can be used to handle tasks like network requests, file I/O, or database operations.

• Coroutines are commonly used in languages like Kotlin, Python, and C++ for asynchronous programming.

Joins are used in databases to combine rows from two or more tables based on a related column between them.

• Joins are used to retrieve data from multiple tables based on a related column between them

• Common types of joins include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN

• Example: SELECT * FROM table1 INNER JOIN table2 ON table1.column = table2.column

Arrays are a data structure that stores a collection of elements of the same data type in a contiguous memory location.

• Arrays have a fixed size determined at the time of declaration.

• Elements in an array are accessed using an index starting from 0.

• Example: string[] names = {"Alice", "Bob", "Charlie"};

Expected CTC depends on the role, experience, and company. It is negotiable based on the candidate's skills and market standards.

• CTC varies based on the job role, experience, and company

• Negotiable based on candidate's skills and market standards

• Salary range can be researched on job portals or company websites

• CTC includes salary, bonuses, and other benefits

• CTC can be discussed during the interview process

Exception handling in coroutines involves handling exceptions that occur during the execution of asynchronous code.

• Use try-except blocks to catch exceptions within coroutines.

• Use asyncio.gather() to run multiple coroutines concurrently and handle exceptions.

• Use asyncio.ensure_future() to convert a coroutine to a Task and handle exceptions.

• Use asyncio.run() to run the main coroutine and handle exceptions.

• Handle specific exceptions using except blocks.

Process flow is a visual representation of the steps involved in a workflow or project.

• Identify the starting point of the process

• List out all the steps involved in the process

• Define the sequence of steps and decision points

• Map out the flow of information or tasks between steps

• Consider feedback loops and potential bottlenecks

• End with the final outcome or goal of the process

Custom theme in Drupal

• Create a new folder in /themes directory

• Create a .info.yml file with theme information

• Create a .theme file for custom functions

• Create a templates folder for custom templates

• Override CSS and JS files as needed

Custom forms in Drupal allow for creating unique user input interfaces.

• Custom forms can be created using Drupal's Form API

• Forms can be created as modules or within themes

• Forms can be customized with validation and submission handlers

• Examples include contact forms, registration forms, and surveys

Date Trunc in Tableau is used to truncate date values to a specified level of granularity.

• Date Trunc function is used to truncate date values to a specific level of granularity, such as year, quarter, month, etc.

• It helps in aggregating data at a higher level of detail than the original date field.

• Example: DATE_TRUNC('month', [Order Date]) will truncate the date values to the month level.

SQL is a domain-specific language used for managing and manipulating relational databases.

• SQL stands for Structured Query Language.

• It is used to communicate with databases to perform tasks like querying data, updating records, and creating tables.

• Common SQL commands include SELECT, INSERT, UPDATE, DELETE, and JOIN.

• SQL is not case-sensitive.

• SQL databases include MySQL, PostgreSQL, Oracle, and SQL Server.