Siemens Energy Control System Engineer Interview Questions and Answers

Q1. What is node js?
Ans. 
Node.js is a runtime environment that allows you to run JavaScript code outside of a web browser.
• Node.js is built on Chrome's V8 JavaScript engine.

• It uses an event-driven, non-blocking I/O model.

• Node.js is commonly used for building server-side applications.

• It has a large ecosystem of open-source libraries and frameworks like Express.js.
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Q2. What is event loop?
Ans. 
Event loop is a mechanism that allows a program to efficiently handle multiple events or tasks concurrently.
• Event loop is commonly used in asynchronous programming to manage tasks that may take varying amounts of time to complete.

• It continuously checks for events or tasks in a queue and executes them one by one.

• Event loop helps prevent blocking of the main thread by allowing non-blocking execution of tasks.

• Popular exam...read more
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Q3. Difference between callback and promise?
Ans. 
Callback is a function passed as an argument to another function to be executed later, while a promise is an object representing the eventual completion or failure of an asynchronous operation.
• Callback is used in traditional asynchronous programming, while promises are used in modern asynchronous programming.

• Callbacks can lead to callback hell or pyramid of doom, while promises provide better readability and error hand...read more
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Q4. What is middlewares in node js?
Ans. 
Middlewares in Node.js are functions that have access to the request and response objects, and can modify or terminate the request-response cycle.
• Middlewares are functions that are executed in the middle of the request-response cycle.

• They can perform tasks like parsing request data, logging, authentication, etc.

• Middlewares can be added using app.use() method in Express framework.

• Example: app.use(bodyParser.json()) to p...read more
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Q5. What is event emitter?
Ans. 
Event emitter is a pattern used to handle and respond to events in software development.
• Event emitter is a design pattern commonly used in Node.js for handling events.

• It allows objects to subscribe to events and be notified when those events occur.

• Event emitter is often used for asynchronous programming and decoupling components.

• Example: EventEmitter class in Node.js can be used to create custom events and handle them.
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Q1. They will ask you about your basic details
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Q1. Work experience and work related Questions which you have done in past
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Q1. Why should we hire you?
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Q2. What are your salary expectations?
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Q3. Share details of your previous job.
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Q1. Functional and Work Experience related.
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Q1. Salary and Location Negotiations
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20 min - 20 questions

Q1. Discussion on background and profile
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Psychometric test happened online

Q1. Core technical related your profile
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Q1. Core technical round
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Q1. Technical & ask about you thought process
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Q1. About your background & skills
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