Senior Backend Developer Interview Questions and Answers

Design an admin dashboard for Uber to display driver metrics like availability over an area.

• Include a map showing driver locations in real-time

• Display driver availability status (online/offline) with color-coded indicators

• Show driver metrics such as total number of drivers, average wait time, and busiest areas

• Allow filtering by specific areas or time periods

• Provide analytics and insights based on driver data

Use binary search to identify odd weight ball among similar balls with minimum steps

• Divide the balls into two equal halves and weigh them

• If one side is heavier, repeat the process with that side

• If both sides are equal, the odd weight ball is among the unweighed balls

Serial and parallel streams in Java are used for processing collections of data in a sequential or parallel manner.

• Serial streams process elements in a single thread, while parallel streams use multiple threads for faster processing.

• Parallel streams can improve performance for large datasets by utilizing multiple cores of the processor.

• Serial streams are suitable for smaller datasets or when order of processing is important.

• Use parallel streams with caution as they may introd...read more

Use array method to extract details about an array of strings

• Use the map method to extract specific details from each element in the array

• For example, use map to extract the length of each string in the array

• Another example is to use map to convert all strings to uppercase

Design a web scale web crawler for efficient and effective data retrieval.

• Utilize a distributed architecture to handle large amounts of data and parallel processing.

• Implement intelligent crawling strategies to prioritize important pages and avoid duplicate content.

• Use efficient data storage and indexing techniques to manage the crawled data effectively.

• Consider scalability, fault tolerance, and monitoring for a robust web crawler system.

Design a web crawler to fetch and index web pages

• Start by identifying the target websites and their structure

• Implement a system to fetch web pages using HTTP requests

• Parse the HTML content to extract relevant information

• Store the extracted data in a database for indexing and searching

• Implement a scheduling mechanism to regularly crawl and update the data

Snake game is a classic arcade game where a player controls a snake to eat food and grow longer while avoiding collisions with walls and itself.

• Create a grid-based game board where the snake can move in four directions (up, down, left, right)

• Generate food randomly on the board for the snake to eat and grow in length

• Implement collision detection to check if the snake hits the walls or itself

• Update the game state continuously based on user input and game logic

• Keep track of the ...read more