Opendoor Senior Software Development Test Engineer Interview Questions and Answers for Experienced

Q1. How can we improve the performance of a Front End System
Ans. 
Improving Front End System Performance
• Optimize images and reduce their size

• Minimize HTTP requests and use caching

• Use lazy loading for images and videos

• Reduce the number of DOM elements

• Use a Content Delivery Network (CDN)

• Minimize the use of external scripts and plugins

• Use asynchronous loading for scripts

• Optimize CSS and JavaScript files

• Use browser caching

• Implement server-side rendering
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Q2. What is Event Loop and give an example on how it works.
Ans. 
Event Loop is a mechanism that allows JavaScript to handle multiple tasks simultaneously.
• Event Loop is a part of JavaScript runtime that continuously checks the call stack and the task queue.

• It prioritizes the tasks in the queue and pushes them to the call stack when it's empty.

• This allows JavaScript to handle I/O operations and other asynchronous tasks without blocking the main thread.

• Example: setTimeout() function ad...read more
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Question on dsa and string theory along with oops concepts

Q1. Question on java strings and arrays
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Some database questions,some java questions .

Q1. What is the difference between javascript and jQuery.
Ans. 
JavaScript is a programming language used for web development, while jQuery is a library built with JavaScript to simplify HTML document traversal and manipulation.
• JavaScript is a programming language, while jQuery is a library written in JavaScript.

• JavaScript can be used for a wide range of tasks, while jQuery is mainly used for DOM manipulation and event handling.

• JavaScript is a core technology for web development, w...read more
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Q2. Define different types of join
Ans. 
Different types of joins are used in SQL to combine rows from two or more tables based on a related column between them.
• Inner Join: Returns rows when there is at least one match in both tables.

• Left Join (or Left Outer Join): Returns all rows from the left table and the matched rows from the right table.

• Right Join (or Right Outer Join): Returns all rows from the right table and the matched rows from the left table.

• Full ...read more
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Q3. Define multithreading concept and exception handling.
Ans. 
Multithreading allows multiple threads to run concurrently, while exception handling deals with errors in a program.
• Multithreading involves running multiple threads simultaneously to improve performance and responsiveness.

• Threads share the same memory space but have their own program counter and registers.

• Exception handling is a mechanism to handle errors or exceptional situations in a program.

• It helps prevent the prog...read more
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Normal and simple js dsa question regarding strings and arrays.

Q1. Box model. Semantic tags Type coersion
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Q1. Responsive web development Bootstrap CSS combinators
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Q1. Javascript questions
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Q2. React Questions on child prop etc
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Q1. Questions about Project and related to .net technologies
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