Xyz Company Backend Developer Interview Questions and Answers

A hackerrank test was shared which had 2 ques to be solved in 60 min in Node.JS. The first one was a simple DS question related to arrays. The second ques was to write routes and controllers for a Node.JS Express app. The routes were GET /projects, GET /project/:id and GET /projects/active

Q1. What is the difference between package and package-lock.json?
Ans. 
package.json lists dependencies and package-lock.json ensures consistent installs.
• package.json lists all the dependencies required for the project

• package-lock.json ensures that the same versions of dependencies are installed across all environments

• package.json is manually edited while package-lock.json is generated automatically

• package-lock.json is used for reproducible builds
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Q2. Write a function that can keep a count of certain functions in our application.
Ans. 
Function to count certain functions in the application
• Create a dictionary to store the count of each function

• Increment the count of the function each time it is called

• Include a reset function to reset the count of all functions

• Example: def count_functions(): function_count = {}

• Example: def function1(): function_count['function1'] += 1

• Example: def reset_count(): function_count.clear()
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Q3. How can we make sure that package versions are taken from package-lock.json and not package.json
Ans. 
To ensure package versions are taken from package-lock.json, use npm ci instead of npm install.
• npm ci installs packages based on package-lock.json

• npm install may update package versions in package.json

• Always commit package-lock.json to version control
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Q4. Create an object and write a function inside it.
Ans. 
Creating an object with a function inside it.
• Create an object using object literal notation

• Define a function inside the object using function expression or declaration

• Access the function using object.method() syntax
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Q5. Given an array that has stock prices from morning till afternoon. Return the best buy and sell price to gain the max profit. For example, input -> [2,5,8,1,3,6,9,3,6], output -> [1,9]
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Q1. 1. Insertion in LL 2. Java core
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Q1. 1. Project related question of internship 2. Python libraries
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Q1. Normal discussion regarding experience
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Q2. Asking about urself and salary expectation
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Q1. System design of iot machine
Ans. 
Designing a system for IoT machines involves creating a network that allows devices to communicate and share data.
• Consider the communication protocols needed for devices to connect and exchange data

• Implement security measures to protect data and prevent unauthorized access

• Design a scalable architecture to handle a large number of devices and data

• Utilize cloud services for storage and processing of IoT data

• Include edge ...read more
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Linked list implementation

A hackerrank test was shared which had 2 ques to be solved in 60 min in Node.JS. The first one was a simple DS question related to arrays. The second ques was to write routes and controllers for a Node.JS Express app. The routes were GET /projects, GET /project/:id and GET /projects/active

Q1. What is the difference between package and package-lock.json?
Ans. 
package.json lists dependencies and package-lock.json ensures consistent installs.
• package.json lists all the dependencies required for the project

• package-lock.json ensures that the same versions of dependencies are installed across all environments

• package.json is manually edited while package-lock.json is generated automatically

• package-lock.json is used for reproducible builds
Answered by AI
Add your answer
Q2. Write a function that can keep a count of certain functions in our application.
Ans. 
Function to count certain functions in the application
• Create a dictionary to store the count of each function

• Increment the count of the function each time it is called

• Include a reset function to reset the count of all functions

• Example: def count_functions(): function_count = {}

• Example: def function1(): function_count['function1'] += 1

• Example: def reset_count(): function_count.clear()
Answered by AI
Add your answer
Q3. How can we make sure that package versions are taken from package-lock.json and not package.json
Ans. 
To ensure package versions are taken from package-lock.json, use npm ci instead of npm install.
• npm ci installs packages based on package-lock.json

• npm install may update package versions in package.json

• Always commit package-lock.json to version control
Answered by AI
Add your answer
Q4. Create an object and write a function inside it.
Ans. 
Creating an object with a function inside it.
• Create an object using object literal notation

• Define a function inside the object using function expression or declaration

• Access the function using object.method() syntax
Answered by AI
Add your answer
Q5. Given an array that has stock prices from morning till afternoon. Return the best buy and sell price to gain the max profit. For example, input -> [2,5,8,1,3,6,9,3,6], output -> [1,9]
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Hacker Renk test with coding problems, need to pass it

Q1. Oops concepts in detail
Ans. 
Object-oriented programming concepts that help in creating modular and reusable code.
• Abstraction - hiding implementation details

• Encapsulation - binding data and functions together

• Inheritance - creating new classes from existing ones

• Polymorphism - using a single interface to represent multiple types

• Composition - combining objects to create more complex ones
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Q2. Oops concepts in technology, design patterns
Ans. 
Object-oriented programming concepts and reusable solutions for common problems.
• Encapsulation, inheritance, and polymorphism are key OOP concepts.

• Design patterns provide reusable solutions for common programming problems.

• Examples of design patterns include Singleton, Factory, and Observer.

• Understanding OOP and design patterns can lead to more efficient and maintainable code.
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Q1. Manager round managerial qualities
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Q2. Work management related questions
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Q1. General plus salary discussions
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Q1. Coin change problem
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