20 Popular System Design Interview Questions

1. Distributed Metrics Logging & Aggregation System
Companies: Google, Facebook, Amazon, eBay, Datadog, Atlassian

2. Distributed Stream Processing System (like Kafka)
Companies: Amazon, Microsoft, Wise, Confluent

3. Key-Value Store
Companies: Apple, Google, Canva, Avalara, Rubrik, OpenDoor

4. K Most Shared Articles in Time Windows (24h, 1h, 5m)
Companies: LinkedIn, Facebook, Twitter

5. API Rate Limiter
Companies: Amazon, Atlassian, Uber, Patreon, Microsoft, Stripe, Headway, Reputation.com, Pinterest

6. Performance Metrics Collection from Thousands of Servers
Companies: Google, Datadog, Amazon, eBay, LinkedIn

7. Google Calendar (or similar scheduling system)
Companies: Google, LinkedIn

8. Distributed Queue (like RabbitMQ)
Companies: Amazon, Apple, Instacart

9. Google Analytics – User Dashboard & Data Pipeline
Companies: Microsoft, Facebook, Qualtrics, Google

10. Sorting Large Data Sets at Scale
Companies: Google, Microsoft

11. Top-K Elements (App Store Rankings, Bestsellers, etc.)
Companies: Amazon, Bloomberg, Facebook, Pinterest

12. Dropbox / Google Drive (Cloud Storage & Sync)
Companies: Dropbox, Facebook, Google, Amazon, Microsoft, Oracle Cloud (OCI)

13. Job Scheduler
Companies: Google, Amazon, Microsoft, DoorDash, Netflix, Atlassian

14. Notification Service at Scale
Companies: Google, Pinterest, OCI, StubHub, Amazon, Airbnb, Instacart

15. Surge Pricing System (e.g., Uber, Lyft)
Companies: Uber, Lyft

16. Netflix – Limit Concurrent Screens per User
Companies: FAANG

17. ETA & Location Sharing Between Driver & Rider
Companies: Uber, FAANG

18. Hotel Booking System (Availability, Reservation, Booking)
Companies: Amazon, Square, Booking.com

19. A/B Testing Platform (like Optimizely)
Companies: Affirm, FAANG

20. Price Alert System (Amazon products, stock/crypto prices)
Companies: Facebook, Bloomberg, Coinbase, Swyftx, Trade Republic