February 08, 2022

Are you preparing for a system design interview at Facebook? The company is consistently named one of the "Best Places to Work" in the business world. This comes as no surprise, given Facebook's corporate culture is built on its core values. Engineers, engineering managers, and technology leads all see Facebook as one of the most desirable employers to work for.

Naturally, Facebook system design interviews are challenging and tough. You'll need to design a high-level architecture for the software system. You'll also need to answer questions and address potential issues that arise from your solution.

However, if you're well-prepared and know what to expect, you'll have a good chance of landing the job. In this blog post, we've compiled all you need to know about Facebook system design interviews to help you prepare.

Facebook Interview Process

The Facebook interview process can be summarized into two steps:

1. Initial Technical Screen/Phone Screen 

2. Onsite Interview

Initial Technical Screen/Phone Screen

The initial technical screen is usually a 30-minute conversation with a recruiter. The recruiter will ask you about your past work experience and why you're interested in the position.

This call is usually very casual, so you shouldn't worry too much about it. The recruiter will then schedule your onsite interview if everything goes well.

Onsite Interview

The onsite interview for the system design position consists of 4-5 45-minute interviews with different people from the team. This includes:

• Behavioral Interview

• Coding Interview

• Design Interview

These are the types of questions you might expect in the onsite interview for a system design position.

Getting Ready for the Facebook System Design Interview

The more you prepare, the easier it will be to answer questions. You must justify every move you make while taking part in a system design interview because it will have to be approved by your interviewer.

There are no shortcuts to acing system design interviews; all you have to do is develop your system design abilities. Below are some tips prepared by our top-rated Recruiters at Recruitmently on preparing for the interview.

Study System Design Concepts

The best way to prepare for a system design interview is to study system design concepts. There are many resources to help you do this. Several books cover various topics, including problem-solving techniques, programming methodologies, and software design principles.

Another option is to watch video lectures on YouTube and other online resources to give you a more in-depth understanding of system design concepts.

If you're short on time, then you can focus on the following key system design areas:

• System Architecture

• Data Structures and Algorithms

• Software Design Principles

In order to stand out in a Facebook system design interview, make sure you detail how you'll use Machine Learning in your design.

Practice Interview Questions

Another way to prepare for a Facebook system design interview is to practice answering interview questions with our dedicated recruiter team. We have access to questions typically asked in Facebook system design interviews.

We also offer Mock Interviews, wherein you can get feedback on your interview skills and improve them. You'll be able to practice with one of our experienced recruiters who will help you make the most of your time. We encourage you to practice as many questions with our recruiters until you feel confident.

Understand the Company and the Role

In order to design a system that is suitable to the company's needs, you need to have a good understanding of what Facebook does. You should have an in-depth knowledge of the role you're interviewing for.

Take the time to research Facebook and learn about its services, products, and competitors. You'll need to know as much as possible about what it does, who its customers are, how many users use their platform every day or month. Try looking at their website and reading their white papers to understand the company better.

The more you know about Facebook and the role, the easier it will be to develop ideas that could potentially improve their system.

Frequently Asked Facebook System Design Interview Question

The Facebook system design interview can be classified based on key concepts — latency, database management systems, proxies, network protocols, availability, and throughput, to name a few. Here are some questions that categorized these system design concepts.

Queues and Pub-Sub

They're intermediate devices that allow messages to be sent asynchronously through the system's communication model. Queues store received messages until the recipient retrieves them, whereas pub-sub sends messages to multiple recipients.

When designing a queue system, the most important thing to remember is scalability and reliability. Here's one of our top Facebook system design interview questions related to queues:

• Design a file storage system like Dropbox

• Design a web crawler service

• Design a Facebook photo-sharing service

SSE, Polling, and WebSocket 

These are three different techniques used to handle communication between the client and server.

SSE stands for Server-Sent Events, which is a technique that allows the server to push updates to the client as they happen. Polling uses intervals to check for updates from the server, whereas WebSocket opens a permanent connection between the two so that data can be exchanged as it happens.

These techniques can be used to design a real-time messaging system, one of the most popular Facebook system design interview questions.

• Design a support service

• Design Instagram

• Design Netflix

• Design Twitter

Sharding, Replication, and Caching

Sharding is splitting data into multiple databases to reduce the load on one database. Replication involves storing copies of the same data in different locations for redundancy purposes; caching stores frequently accessed information to be retrieved faster when needed.

Data sharding and replication are fundamental aspects of designing a large-scale system. Here are some of our top Facebook system design interview questions related to these concepts:

• Design a web crawler service

• Design a file storage system such as Google Drive

• Scale Stack Overflow

• Designing Flickr

• Designing BookMyShow

• Designing the Twitter timeline

• Designing Facebook's newsfeed

Leader Election and Consensus

In a distributed system, it's important to select one processor node as the leader. The leader is responsible for making decisions that affect the entire system.

Consensus refers to the agreement of all nodes in the system on any decision made by the leader. It's important to have consensus algorithms to ensure that all nodes agree on the same decision. Here are our top Facebook system design interview questions related to leader election and consensus:

• Design a Distributed Message Queue

• Design and implement leader election with Kubernetes

• Implement Leader Election in a cloud service such as Google

Load Balancing

It's essential to balance the load among different nodes in the system. The two techniques used for this purpose are Round-Robin and Consistent Hashing.

In Round Robin, requests are served by a node sequentially; consistent hashing involves assigning each node a unique hash that is then used to determine where requests should be routed. Here are some of our top Facebook system design interview questions related to load balancing:

• Design BookMyShow

• Design a Cloud Gateway for Netflix

• Design Pinterest

• Design a scalable AWS system

• Design Instagram

Availability, Latency, and Throughput

In order to create a high-availability system, it's essential to understand the concepts of availability, latency, and throughput. Availability is the percentage of the system's time that is available for use. Latency is the time it takes for a request to be processed. Throughput is the number of requests systems can handle in a certain period of time.

Here are some of our top Facebook system design interview questions related to availability, latency, and throughput:

• Design a financial management app like Mint.com

• Design the Twitter timeline and search feature

• Design a live commenting feature for Facebook

Database Management Systems

DBMS is a software system managing the creation, storage, and retrieval of data from a database.

There are many different DBMS types, each with its own set of features. It's important to choose a suitable DBMS for the job. Here are some of our top Facebook system design interview questions related to DBMSs:

• Design an online text-sharing tool like Pastebin

• Choose a DBMS for a social networking site

• Design a system to store sensor data

• Design an image storing and sharing platform like Flickr

• Design file storage and sharing systems like Dropbox

Network Protocols and Proxies

A network protocol is a set of rules for communicating over a computer network. It specifies the format, timing, and sequence of messages that computers must use to exchange data with each other.

There are many different types of network protocols, including TCP/IP (Transmission Control Protocol/Internet Protocol), UDP (User Datagram Protocol), FTP (File Transfer Protocol), and SMTP (Simple Mail Transport Protocol).

A proxy server is a computer that sits among the client and the server, handling the client's requests and forwarding them to the servers. It can also cache responses from the servers, improving performance. Here are some of our top Facebook system design interview questions related to network protocols and proxies:

• Design a proxy server for a social networking site

• Implement an FTP proxy

• Cache web pages using HTTPCache

• Develop an SMTP relay server

These questions will help you prepare for Facebook system design interviews by providing practice in the areas of consensus, load balancing, availability, latency, and throughput. It's important to understand these concepts and how they relate to each other because they'll be used frequently during your interview.

These questions will also give you an idea of what kind of problems you might encounter during your interview. You'll be able to understand how Facebook works and what kinds of things they're looking for when hiring new employees.

Sample Problems for Facebook System Design Interview

1. How would you design a search engine? 

2. How would you improve the performance of a social networking site?

3. How would you handle scaling issues for a photo-sharing website?

4. Design a system to prevent DDoS attacks

5. How would you design a shared drive?

6. How would you enhance the availability of a website?

7. Design a Fact-Check feature for Facebook

8. Design a system to handle user reports

9. How would you design Autocomplete feature for Facebook?

10. How would you implement facebook's feed?

11. What is the best way to store a large amount of data in memory? 

12. How would you optimize performance when loading images from a disk?  

13. How would you design facebook's chat system?

14. Design a video-streaming platform like Youtube or Netflix

15. How would you prevent spam when sending bulk emails from Facebook? 

16. How does Facebook manage all those users and their messages in real-time without lag on Facebook messenger?

17. How would you design facebook's notification system? 

18. Design a facebook-like game platform

19. Design feed for Facebook/Twitter-like websites. How do you keep the feeds updated in real-time?

20. Design a type-ahead service

FAQs on Facebook System Design Interview Questions

What sorts of questions are asked during Facebook's system design interviews?

Facebook system design interview questions can vary, but some of the most common ones include problems related to consensus, load balancing, availability, latency, and throughput. You may also be asked to solve sample problems or design a specific feature.

Is the Facebook system design interview conducted online?

A typical Facebook system design interview is conducted onsite on a whiteboard. However, more recently, it's become common to conduct such interviews online using video conferencing software such as Zoom or Skype.

How long does the Facebook system design interview last?

A Facebook system design interview can last for 45 minutes.

It's Getting Easier to Ace the Facebook Interview

If you have failed to pass the Facebook system design interview in your past, don't worry. Recruitmently can connect you to our top-rated recruiters who can help you ace the Facebook interview, providing career advice, interview tips, and resources.

Recruitmently's coaches have helped thousands of people land their dream jobs by providing them with interview preparation and career advice. Our recruiters are here to help you get your foot in the door at some of the world's top companies, including Facebook. We have helped many people get hired, and we can help you too. We have expert networks of coaches to help you land the job of your dreams.