Meta System Design Interview Questions – Ultimate Guide to Ace the Interview

Meta's unique considerations in system design

Meta considers the below unique concepts in their system design interview questions.

• Horizontal Scaling: They sometimes ask how you can design a system such that you can increase the servers when the number of users increases. Learn more about horizontal scaling.

• Sharding: The sharding allows breaking down the data into smaller components and distributing them across multiple servers to manage efficiently.

• Global Distribution: They may ask you to explain how you can distribute the data globally so that users can access data with low latency.

• Machine Learning and AI Integration: The meta uses various AI and machine learning algorithms in their applications. So, they can ask questions like how the recommendation system works to serve the personalized content.

• Real-time processing: The Messenger application of Meta allows for real-time communication. So, they also ask questions like how you can process the real-time message queues with low latency.

You can learn 18 system design concepts every engineer should know before the interview.

Common Meta System Design Interview Questions

In the previous section, you have seen the system design interview process at Meta, what resource you should refer for the preparation, and what concepts you should focus more on.

Now, let’s get into solving the real-time system design question, which was asked in the Meta system design interview in the past years.

1. Design a news feed algorithm

"How would you design the Facebook news feed?" is the most common question asked in the Meta system design interview. For the question, you should consider the below functional and non-functional requirements.

Functional requirements:

• The system should show various posts to people from other people.
• Users should be able to follow other people and Facebook pages.
• Users should be able to comment on the news post.

Non-functional requirements:

• Lowest latency to decrease the lag.
• The system should be able to prepare a news feed for any user according to their followings and trending news.

Points to discuss:

• For the high-level system design, you can discuss how you will allow users to publish the news and generate a news feed for a particular user.

• Discuss implementing the recommendation engine to generate the new feed using the AI and ML algorithms.

• Discuss the data modeling. For example, which database you will choose, like RDBMS or NoSQL, and why you have chosen the particular one.

• Next, discuss how you can do load balancing across multiple servers.

However, the interviewer may ask you to clarify some more factors, and you can also discuss that.

2. Design Messenger

If you have asked ‘how you would design Facebook Messenger or WhatsApp’, you can consider the functional and non-functional requirements below.

You may also ask the interviewer for more requirements in the system.

Functional requirements:

• The system should allow a one-to-one encrypted algorithm.

• The system should also support the group chat conversation.

• The system should store the chat history.

Non-functional requirements:

• Design a highly available system. • Design a highly consistent system so users can see messages in the same order. • High latency is required for the real-time system design.

Points to discuss:

• Discuss how clients will maintain a connection with the server.

• Discuss which protocols you will use for the communication. For example, you can discuss that TCP can be used as packet loss is not allowed.

• Next, discuss implementing the encryption and decryption algorithm to provide an end-to-end description.

• Discuss data modeling and how you will store the chat history in the database.

• Discuss how you will handle the multiple requests simultaneously and what will happen if both users try to send messages simultaneously. How will you make it consistent?

• Discuss how the system’s server will send messages to offline users.

Learn how to design Messenger.

3. Design an Instagram

If you have been tasked with designing a system similar to Instagram, you can consider the functional and non-functional requirements.

Functional requirements:

• Users should be able to upload images, long videos, and short videos.

• Users should be able to connect with other users.

• Users should be able to go live with multiple users.

Non-functional requirements:

• Prepare a highly reliable system so users don’t lose a fraction of uploaded media.
• Prepare a highly available and consistent system.

Points to discuss:

• Discuss storing the user’s data like posts, videos, usernames, passwords, profile descriptions, etc. in the database. You may use the relational databases.

• Discuss implementing the recommendation algorithm.

• Discuss using UDP protocol for live streaming.

• Discuss implementing CDN for the low latency.

Learn how to design Instagram.

4. Design Ticketmaster

In the Meta system design interview, the interviewer may ask you how you would design an online ticket platform. you may follow the approach below to solve the problem.

The online ticket platforms allow users to book movie tickets.

Functional requirements:

• The system should show all cinemas with location.

• Allowing users to register on the portal and book a ticket in any cinema for a particular movie show.

• Don’t allow booking already booked seats.

• Users should be able to reserve a sheet for a particular time before booking.

Non-functional requirements:

• Need to make the app secure.
• Handle more than 1 booking request for the same sit simultaneously.

Points to discuss:

• Discuss implementing the authentication and authorization to access users to tickets they booked only.

• Discuss the database you can use to store the cinema data like location, already booked seats, and movie shows. Also, discuss how you would maintain user data in the database.

• Also, discuss using the protocols like HTTPs for security reasons.

• Discuss how you would block one user for a fraction of the time if two user tries to book the same seat simultaneously.

• Discuss implementing the caching mechanism to reserve the seat for a particular time before booking to make the application more concurrent.

Learn how to design ticketmaster.

More System Design Interview Questions for Meta

• Design an ad click analytics/aggregator system – How to collect and process billions of ad click events in real-time, ensuring accurate counts and insights for advertisers.

• Design a “Top K” trending topics service – For example, determine the top 10 trending hashtags or search queries at any given time, updating continuously as new data streams in.

• Design Facebook Live Comments – A system to handle live streaming comments in real-time (as seen in Facebook Live videos), which must fan-out updates to thousands of viewers with minimal latency.

• Design a distributed file storage system – Think along the lines of a simplified Google Drive or Dropbox, where users can upload files that are stored redundantly across data centers for durability and quick access. (Focus on storage sharding, metadata service, replication, and consistency.)

• Design an autocomplete suggestion service for search – For instance, when a user types in the search box, how to quickly suggest relevant completions (as used in Facebook search or Instagram search) by querying a large dataset of terms with minimal latency.

• Design an online auction or marketplace system – For example, a platform where users can list items and bid in real-time (similar to eBay, or Instagram live auctions). Consider user sessions, real-time bid updates, and consistency when finalizing sales.

• Design a secure user authentication service – A system to manage login and authentication for millions of users (like “Login with Facebook”). It should handle password verification, manage user sessions/tokens, support features like multi-factor authentication, and guard against attacks (rate limiting, account lockout, etc.).

• Design a content moderation system – How to automatically detect and filter out inappropriate or harmful content at scale (for a platform like Facebook). This could involve an ingestion pipeline, machine learning classification, a human review tool, and real-time enforcement. (Focus on processing pipeline and reliability, as well as reporting/dashboards for moderators.)

System Design vs. Product Design at Meta

Meta distinguishes between System Design and Product Design interviews, and it’s important to understand which one you’re facing (in fact, candidates are often given a choice between the two).

Both interview types involve designing a system on the fly, but they differ in focus and context:

• System Design Interview (Backend Focus): This format centers on large-scale distributed systems. You’ll be asked to design the backend architecture for something that needs to handle massive scale or heavy throughput. For example, you might design an infrastructure component like a caching system, a message queue, or an analytics pipeline. The emphasis is on scalability, reliability, partition tolerance, and performance. Interviewers will expect you to discuss low-level components (datastores, caches, load balancers, etc.) and how to make the system resilient and efficient under large load. It’s common for infrastructure or platform engineering roles, or anyone with deep backend experience.

• Product Design Interview (User-Facing Focus): This interview is geared toward designing an end-to-end product or feature that users interact with. You’ll be asked to design a high-level system for a product – for example, designing Instagram Stories, Facebook News Feed, or a ride-sharing app backend. The focus here is on application behavior, APIs, data models, and user experience flows. You’ll still discuss backend components, but the scope includes how the frontend, clients, and backend services work together to deliver features. It’s suited for candidates who have worked on user-facing products, where understanding feature requirements and client-server interaction is key.

Which one will you face? Meta may allow you to choose the interview type based on your strengths or background. If you’re a backend or systems engineer, you might opt for System Design, whereas a full-stack or product-focused engineer might choose Product Design.

In either case, the question prompt could be similar – e.g. “Design Facebook News Feed” could appear in both. The difference lies in what you emphasize: in System Design, you’d dive into scaling the feed for billions of requests (caching, fan-out, etc.), whereas in Product Design, you’d focus more on features, ranking algorithms, and how the user interacts with the feed.

Evaluation criteria for each: Interestingly, Meta uses similar core competencies to evaluate both interview types (problem solving, solution design, technical knowledge, communication). However, the lens is slightly different:

• In a System Design interview, they’ll judge how well you handle technical complexity at scale – e.g. partitioning data across servers, ensuring consistency vs. availability, optimizing for high throughput. Your design choices should demonstrate that you can build a robust infrastructure for millions of users.

• In a Product Design interview, they’ll look at how you meet product requirements – are you capturing the right features, defining clear APIs, and providing a great user experience? There’s more weight on how the system’s design translates to product functionality and user impact. For instance, you might be evaluated on how intuitively you design an API or how well you consider user privacy and security in the product’s architecture.

Despite these nuances, remember that both interview types overlap a lot.

It’s not a big deal if your Product Design interview touches on scaling, or if your System Design answer mentions some user-facing considerations – the interviewer will guide you if needed.

The key is to show you can design a system that works well for its intended purpose, whether that’s a generic backend service or a specific product feature.

How to Answer Meta (Facebook) System Design Questions

Facing a Meta system design question can be daunting, but a structured approach will help you cover all the bases. Here’s a step-by-step method to tackle these questions, along with best practices:

1. Clarify Requirements and Scope – Start by making sure you truly understand the question. Ask clarifying questions about the product’s core purpose and scope: “What exactly should the system do? Who are the users? What are the must-have features?” Identify both functional requirements (features, behaviors) and non-functional requirements (scale, latency, consistency, security needs). For example, if asked to design a URL shortener, confirm if they expect support for custom URLs, analytics, etc., and how many requests per second we need to handle. This is also the time to state assumptions (e.g. “Let’s assume 100 million active users”) and confirm any constraints. By the end of this step, you and the interviewer should agree on what problem you’re solving before you dive into solving it. (Tip: Aim to keep this part brief – ~5 minutes – so you have plenty of time to design .)

2. Outline a High-Level Design – Next, sketch out the high-level architecture. Break the system into core components and explain how they interact. A common approach is to draw a block diagram with clients (web/mobile), servers, databases, external services, etc. For Meta-scale systems, it helps to think about the scale early: for instance, mention if we’ll use a load balancer to distribute traffic or if we need a content delivery network for global users. Estimate rough numbers (like “we expect 10k requests/sec, so I’ll plan for X application servers”) – this shows you’re considering scalability from the start. At this stage, keep it broad: for each component, just state its role (e.g. “Users hit an API gateway, which then talks to our service layer; we’ll have a database to store user data, and a cache for quick reads”). If relevant, decide on major tech choices now – for example, SQL vs NoSQL database for storing data – based on the requirements (consistency vs partition tolerance, etc.). This high-level plan is essentially your blueprint before drilling into details.

3. Design Deep Dive (Focus on Key Components) – Once the skeleton is in place, start filling in details. Typically, you’ll pick one or two areas of the design to dive deeper into, often guided by the interviewer’s hints or the most critical parts of the system. Begin fleshing out how components work: define your data model (what data will you store? which database tables or data structures?), outline important algorithms or workflows (how will new content propagate to users? how do we handle write vs read traffic?), and address any bottlenecks. It’s crucial to discuss how your design handles the expected scale: Will you partition (shard) the database to handle millions of users? Do you need a cache to reduce read load and latency? How will you handle peak traffic or failures (maybe a queue for buffering writes, or replication for redundancy)? As you explain, draw and annotate the diagram further – e.g. add a cache next to the database with an arrow, sketch multiple server instances behind the load balancer, etc. Remember to think out loud about trade-offs (“I’ll use a NoSQL DB here for flexibility and scalability, but the trade-off is weaker consistency, which is acceptable for our use-case.”). If the interviewer asks a follow-up (“What if the cache goes down?”), be prepared to adjust or elaborate. This step is where you demonstrate depth, so try to show off your knowledge of how to make systems scalable and robust (use concepts like replication, eventual consistency, batching, etc., appropriately). Also, it’s often wise to prioritize: if time is running, focus on the most important part of the system first (for a social network feed, for example, the ranking/distribution mechanism is key). Throughout the deep dive, continue engaging the interviewer: check if they want to explore a particular component or if they are satisfied with the level of detail.

4. Wrap Up with Trade-offs and Improvements – In the last few minutes, summarize your design and make sure you’ve met the requirements you outlined. It’s a good idea to quickly recap: “So we have A, B, C components, which together handle the use-case – we can serve X requests/sec, with data persisted redundantly, etc.” Double-check any specific goal: Did we account for security? What about eventual consistency or data backups? If you realize you missed something minor, you can mention it now (“We might also want to add an analytics service later for logging events – not core to the design, but worth noting.”). This is also the time to discuss trade-offs and alternative approaches. No design is perfect – acknowledge any conscious decisions you made (“We chose SQL for simplicity, but a NoSQL solution could handle scaling differently. That’s a trade-off between consistency and ease of use.”). Interviewers appreciate when you recognize the pros and cons of your decisions. If appropriate, suggest a future improvement or feature: for instance, “In a real system, we’d also build an admin tool to moderate content, but that’s outside today’s scope.” Ending with a clear recap and a reflection on trade-offs shows maturity in design thinking.

Throughout this process, communicate your reasoning at each step – don’t just draw silently. Meta’s interviewers want to hear why you make each choice.

If you consider multiple options (SQL vs NoSQL, or pushing vs pulling data, etc.), talk through your thought process and then state your decision.

Also, adapt to feedback: if the interviewer steers you toward a certain aspect (“Let’s focus on how to make this real-time”), take that cue and allocate your time accordingly.

Demonstrating a structured approach with clarity is just as important as the final design you propose.

Best Practices and Common Pitfalls

• Manage your time and depth: It’s important to cover both high-level architecture and some deep dives. Don’t get stuck endlessly analyzing requirements or one tiny part of the system. For example, spend only a few minutes upfront clarifying requirements (roughly 5 minutes), and don’t design every minor detail of an unimportant component while ignoring major parts. Keep an eye on the clock and ensure you progress through outlining, detailing, and wrapping up.

• Use what you know (avoid buzzword bingo): Stick to components and technologies you understand well. It’s fine if you haven’t used the trendiest new database – you can solve most design problems with fundamental building blocks. Interviewers will notice if you drop fancy terms without context. In fact, at Meta it’s a “dead giveaway” when a candidate throws around buzzwords (like mentioning Kafka or Cassandra for no reason) and can’t explain them. It’s better to use simpler solutions you can describe than to name-drop something you can’t defend.

• Engage and adapt: Treat the interview as a collaborative design session rather than a monologue. After explaining a chunk of your plan, pause and ask “Does that make sense?” or “Would you like me to go deeper on any part?” This gives your interviewer a chance to guide you or ask questions. Many interviewers have a mental checklist and will appreciate you checking in. Candidates who talk non-stop for 30 minutes without interaction risk going off-track. By periodically soliciting feedback, you can make sure you’re focusing on what the interviewer cares about and demonstrate strong communication skills.

• Highlight trade-offs: Great system design answers discuss not just what you chose, but why. If you considered two approaches (e.g. strong consistency vs eventual consistency for a database, or monolithic vs microservices architecture), briefly compare them and explain your choice. This shows you understand the design’s implications. It’s also a chance to showcase critical thinking – every design involves trade-offs in complexity, performance, cost, etc., and Meta’s interviewers want to see that you can weigh these factors. Just be sure to keep the discussion relevant to the problem at hand (don’t dive into a tangent that isn’t going to be evaluated).

By following these practices – structuring your answer, communicating clearly, and demonstrating balanced decision-making – you’ll greatly increase your chances of acing Meta’s system design interview.

Remember, the goal is not only to design a workable system, but also to show confidence and clarity in how you approach open-ended problems.

How to Structure Your Preparation Plan

Here is the step-by-step preparation plan that you should follow for your Meta system design interview. Even if you don’t know system design, follow the steps below to start preparation from scratch.

Step 1: Learn the Fundamentals of system design

The first step to preparing for the system design interview is learning the fundamental concepts of the system design. You can use the online courses, books, etc., recommended in this guide to clear fundamental concepts of the system design. However, you can also choose another course or book to prepare if you find the best.

Step 2: Practice real-time questions

After learning the fundamental concepts of system design, you should practice solving the real-time complex questions that Meta asks in past interviews.

You can refer to the Groking System Design Interview course by Design Guru to practice real-time questions with solutions.

Step 3: Mock Interviews and Practice

The next step is to practice with system design mock interviews, in which you can solve the questions in a specific time, like real-time interviews. Also, you can ask your mentors to conduct your mock interviews.

Step 4: Stay informed

Before going for the interview, you should do some research about current industry and technology trends like artificial intelligence, machine learning, virtual reality, social networking, etc.

Also, it would help if you do company research, like what technology Meta is working on and about company products.

Tips for Acing Your Meta System Design Interview

In tech giant companies like Meta, interviewers don’t just evaluate your technical skills, but they also test your mindset of accepting the challenges and finding the solutions for complex problems.

Here, I’ve given some tips that you need to consider before your interview.

1. Preparing your mindset for success

Consider the tips below.

• Be confident: Take a deep breath and stay calm. You should be confident in your ability and knowledge. Confidence helps you communicate with the interviewer effectively. Don’t be nervous even if you will give your first interview.

• Problem-solving attitude: Whenever an interviewer asks any system design question, you should understand the problem first. After that, you must ask him about the requirements. Next, you can break down the complex problem into small tasks and solve each. It shows your eagerness to solve problems.

• Take feedback: You should always take feedback from the interviewer. If the interviewer gives you any suggestion, you should adapt it and improve your solution. In short, you should be flexible with your solution approach.

• Practice whiteboarding: If you are allowed to draw diagrams on the whiteboard, you should do that. It will help the interviewer to visualize your approach, and they will understand in a better way.

• Practice, practice, practice: Before you go for the interview, you should solve more and more practice questions to build confidence.

2. Dressing appropriately for Meta-interviews

Before you go for the Meta system design interview, it is important to dress appropriately. You can wear casual clothes, with a watch, and shoes. Try to be simple and look professional.

You may also research the culture of Meta and dress accordingly.

3. Time management and communication during the Interview

In the interview, it is important to manage time and communicate effectively.

If you don’t know how to approach the question’s solution, you may ask the interviewer for feedback. They will definitely help you to start but don’t waste time if you don’t know the answer. It might happen that you know the solutions to all the questions that the interviewer is going to ask next.

Positive communication is the key to success. Even if you are thinking about the solution to the problem, you should speak your thoughts, also. So the interviewer can know your approach to solving the problem and evaluate your skills better.

Furthermore, listen actively to the interviewer. So you can understand the problem and give a better answer. It makes more of an impression if you summarize your solution at the end.

Conclusion

The Meta system design interview can be cracked with the above tips. You should be ready with the knowledge of the fundamental concepts of the system design before your interview. Also, you should have done the practice by solving the past interview questions given in this guide and others available on the internet.

For further resources, you can enroll in the Grokking the Advance System Design Interview to get advanced knowledge of system design. Also, read Mastering the System Design Interview: A Complete Guide.

Top 5 FAQs About Meta System Design Interviews

1. What is a Meta system design interview and who has to take it?
   It’s a 45-minute interview round where you’re asked to design a large-scale system. At Meta (formerly Facebook), mid-level and senior engineering candidates (L4 and above) typically get 1-3 system design interviews as part of the on-site process. You won’t write code; instead, you’ll discuss high-level architecture for a hypothetical product or feature. It’s about demonstrating how you design scalable, reliable systems and communicate your thought process.

2. What’s the difference between Meta’s System Design and Product Design interviews?
   Meta has two flavors of design interviews. A System Design interview focuses on back-end distributed systems – designing for massive scale, data handling, and infrastructure (think availability, scalability, storage, etc.). In contrast, a Product Design (or Product Architecture) interview centers on user-facing products – designing features, APIs, and data models with the end-user experience in mind. The question prompt might even be the same in both cases, but system design interviewers will probe more on backend scalability and reliability, whereas product design interviewers dig into API design, data modeling, and user interactions.

3. What are interviewers evaluating in a Meta system design round?
   They want to see architecture skills, analytical thinking, and communication. Concretely, you’ll be judged on how well you address scalability (can your design handle 10× or 100× growth?), reliability (will it stay up and consistent?), and efficiency (resource use and speed). They also look at your understanding of fundamental tech (databases, caches, etc.) and whether you make sensible trade-offs. Equally important is clear communication – explaining your ideas and reasoning so that others (including non-specialists) can follow. In short, Meta interviewers are checking if you can design a sound system and articulate your thought process.

4. How should I prepare for Meta’s system design interview?
   Start with system design fundamentals. Make sure you understand concepts like caching, load balancing, database sharding, queuing, and the CAP theorem. Meta often bases questions on its own products, so study Meta’s main products (News Feed, Messenger, Instagram, etc.) – many design questions are variants of these. Practice by designing different systems out loud or on a whiteboard to get comfortable. It helps to read books or resources (for example, Designing Data-Intensive Applications by Kleppmann or Alex Xu’s System Design Interview guide) for frameworks and examples. Finally, do mock interviews if you can, to simulate the 45-minute pressure and get feedback.

5. What are common mistakes to avoid in a Meta system design interview?
   A few pitfalls trip up candidates frequently. (a) Don’t spend too long on requirements gathering – clarify the goals quickly, but try to keep it to a few minutes so you have time for the actual design. (b) Avoid throwing in buzzwords or components you can’t explain – interviewers can tell if you mention something like CAP theorem or Kafka without understanding it, and they will press you on it. (c) Don’t turn it into a one-way monologue; pause periodically to check in with your interviewer. Many Meta interviewers will let you drive, so it’s up to you to engage them – ask if your approach makes sense or if they have a preference for what to tackle next. By managing time well, sticking to what you know, and treating it as a collaborative discussion, you can avoid these common mistakes.