10+ Pfizer Interview Questions and Answers

Design a system to display real-time updates of a file's content on a webpage.

• Use a server-side programming language like Node.js to read the file content.

• Implement a WebSocket connection between the server and the webpage for real-time updates.

• Whenever the file is updated, send the updated content to the webpage using the WebSocket connection.

• Update the webpage dynamically using JavaScript to display the new content.

To add two numbers represented as linked lists, iterate through both lists simultaneously, adding corresponding digits and carrying over the carry value.

• Create a new linked list to store the result.

• Initialize a carry variable to 0.

• Iterate through both linked lists simultaneously, adding the corresponding digits and the carry value.

• If the sum of the digits is greater than 9, update the carry value and store the remainder in the result list.

• Move to the next nodes in both lists....read more

When we click on a URL, the browser sends a request to the server, which responds with the requested webpage.

• Clicking on a URL triggers the browser to send an HTTP request to the server.

• The server receives the request and processes it.

• The server then sends back a response containing the requested webpage.

• The browser receives the response and renders the webpage for the user to view.

High-level component structure of a page refers to the organization of the main elements on a webpage.

• Identify the main content area of the page

• Determine the navigation menu and its placement

• Decide on the placement of secondary content such as ads or related articles

• Consider the footer and its contents

• Ensure the page is responsive and adaptable to different screen sizes

Implementing tail -f command without external libraries in Python

• Open the file in read mode

• Use a loop to continuously read new lines added to the file

• Print the new lines as they are read

Async is non-blocking, concurrency is managing multiple tasks at the same time, parallelism is executing multiple tasks simultaneously.

• Async allows non-blocking execution of code, enabling other tasks to run while waiting for I/O operations.

• Concurrency involves managing multiple tasks at the same time, but not necessarily simultaneously.

• Parallelism is executing multiple tasks simultaneously, utilizing multiple CPU cores for faster processing.

• Example: Async programming in Java...read more

I have worked on various projects involving software development and implementation.

• Developed a web application for a retail company to manage inventory and sales.

• Implemented a mobile app for a healthcare organization to track patient data and appointments.

• Created a data analysis tool for a financial institution to analyze market trends and make investment decisions.

Google.com is a search engine that uses web crawlers to index websites and algorithms to rank search results.

• Google uses web crawlers to index websites and store information in its database.

• Algorithms are used to rank search results based on relevance and popularity.

• Google also uses personalized search results based on user data and location.

• Google's homepage is simple and fast-loading to provide a user-friendly experience.

A chat app using sockets allows real-time communication between users.

• Use a socket library or framework to handle the communication.

• Implement a server that listens for incoming connections and manages the chat rooms.

• Establish a socket connection between the server and clients for sending and receiving messages.

• Handle message encryption and decryption for secure communication.

• Implement features like user authentication, chat room creation, and message history.

• Consider scalabil...read more

Scaling up an existing project involves optimizing performance, increasing capacity, and improving efficiency.

• Identify bottlenecks and areas for improvement

• Implement caching mechanisms to reduce load times

• Optimize database queries for faster retrieval

• Upgrade hardware or infrastructure to handle increased traffic

• Use load balancing to distribute traffic evenly across servers

Implement a tail -f logger in code

• Use a file pointer to open the log file

• Read the file line by line and print new lines as they are added

• Use a loop to continuously check for new lines in the file