Top Meta/Facebook System Design Interview Questions

Landing a software engineering role at Meta requires acing the system design interview, where you’ll demonstrate your ability to architect scalable, reliable systems. If you’re preparing, sign up for our free course updates and exclusive resources to get the latest tips on mastering these challenges.

• Research suggests Meta focuses on real-world scalability: Questions often involve handling billions of users, emphasizing low latency and high availability.
• Common themes include social features and infrastructure: Expect designs around feeds, messaging, and distributed systems, with trade-offs in consistency and performance.
• Preparation is key amid competition: Evidence leans toward practicing 30+ questions, as interviews test depth in trade-offs rather than perfect solutions.

Why System Design Matters at Meta

Meta’s interviews assess how you’d build features like News Feed or Messenger, which serve massive scale. It seems likely that questions draw from actual product challenges, testing your grasp of distributed systems and user-centric design.

Top Categories of Questions

Social media designs (e.g., feeds, recommendations) dominate, followed by infrastructure (e.g., caching, rate limiting). For foundational skills, explore our DSA course to strengthen algorithmic thinking.

Actionable Preparation Tips

Start with high-level overviews, then dive into details. Use resources like our master DSA, web dev, and system design course for structured practice. If time is short, try the crash course.

Preparing for a Meta system design interview can feel overwhelming, but understanding the patterns and practicing real questions makes it manageable. This comprehensive guide explores the top questions asked at Meta, based on recent reports from sources like Glassdoor, LeetCode, and interview prep platforms. We’ll cover the interview process, key concepts, and provide detailed breakdowns of 35 high-quality questions actually asked in interviews, complete with in-depth solutions. Our goal is to equip you with the knowledge to approach these with confidence, drawing from expert insights and best practices.

The Meta System Design Interview Process

Meta’s system design round typically lasts 45-60 minutes and is for mid-to-senior roles. You’ll collaborate with the interviewer to design a system, starting vague and building depth. Expect to clarify requirements, sketch high-level architectures, and discuss trade-offs. As per reports from IGotAnOffer, questions often stem from Meta’s products, like designing Instagram or a messaging app. The focus is on scalability for billions of users, low latency, and reliability. Prep by reviewing distributed systems principles—interviewers value clear communication over flawless designs.

Key evaluation criteria include:

• Problem understanding: Ask clarifying questions on functional (e.g., features) and non-functional requirements (e.g., scale, latency).
• High-level design: Outline components like clients, servers, databases, and caches.
• Detailed dive: Zoom into critical parts, like data modeling or handling failures.
• Trade-offs: Discuss pros/cons, such as CAP theorem implications.
• Scalability and bottlenecks: Address growth, like sharding or replication.

Stats from Exponent show over 79 questions in their database, with social features like feeds (appearing in 20% of reports) being common. Glassdoor data (2025) indicates a 30% pass rate for this round, highlighting the need for thorough prep.

Essential Concepts for Meta Interviews

Before diving into questions, master these topics, as noted in GeeksforGeeks and Educative:

• Scalability: Horizontal vs. vertical scaling, load balancing.
• Databases: SQL vs. NoSQL, sharding, replication.
• Caching: Strategies like LRU, distributed caches (e.g., Memcached).
• Distributed Systems: CAP theorem, consensus (e.g., Paxos), fault tolerance.
• APIs and Microservices: REST/GraphQL, event-driven architectures.
• Performance: Latency reduction via CDNs, rate limiting.
• Security: Authentication, encryption for user data.

For broader skills, consider our web development course to understand full-stack implications, or the data science course for recommendation systems.

Top 35 Meta System Design Interview Questions and In-Depth Answers

We’ve curated 35 questions from actual Meta interviews (sourced from Glassdoor, LeetCode, DesignGurus, Exponent, IGotAnOffer, GeeksforGeeks, and Educative in 2025). Each includes functional/non-functional requirements, high-level design, detailed components, trade-offs, and bottlenecks. Questions are categorized for ease.

Social Media Features

1. Design Facebook News Feed Functional: Show posts from friends/pages, support likes/comments/shares, personalized ranking. Non-functional: Low latency (<200ms), high availability (99.99%), scale to 1B+ users. High-level: Clients → Load Balancer → Feed Servers → Ranking Service → Databases (NoSQL for posts, Graph DB for relationships). Detailed: Use fan-out for pre-computing feeds (push model for active users, pull for others); ranking via ML (EdgeRank: affinity, weight, time decay). Cache recent feeds in Redis. Trade-offs: Fan-out vs. fan-in (write-heavy vs. read-heavy); eventual consistency for scalability. Bottlenecks: Ranking compute—use sharding by user ID. Expert quote: “Feeds must balance relevance and recency,” per Meta engineer on LeetCode.
2. Design Facebook Messenger Functional: Real-time 1:1/group chat, media sharing, read receipts, offline support. Non-functional: Low latency (<100ms), end-to-end encryption, scale to 1B messages/day. High-level: Clients (WebSocket) → Gateway Servers → Message Brokers (Kafka) → Storage (Cassandra). Detailed: Use WebSockets for bidirectional comm; encrypt with Signal Protocol; store history sharded by conversation ID; handle offline via push notifications (FCM/APNS). Trade-offs: TCP for reliability vs. UDP for speed; strong consistency for message order vs. availability. Bottlenecks: High concurrency—use consistent hashing for partitioning.