100+ System Design Interview Questions and Problems for Software Engineers

Hello guys, if you are preparing for System Design interviews then you may know that you have to prepare for theory questions as well as System design problems where you need to design a real world system like WhatsApp, YouTube or DropBox. Theory questions are mostly based upon System design basics and core concepts like Scalability, Caching, database sharding, load balancer, API gateway, security, proxies, messaging queues and software architecture, particularly Microservices. I have been sharing a lot of system design preparation material from last few years, in for example, in the past, I have shared System Design Interview Prep Guide as well as best System design interview books, courses, cheat sheets, and websites and in this article, I am target to share 100+ System Design Interview questions as well as System Design Problems.

100+ System Design Interview Questions and Problems for Practice

Without any further ado, here is a list of popular System design interview questions and problems you can practice for interviews. I have included both theory questions like API Gateway vs Load Balancer, or Microservices vs Monolithic architecture and system design problems like designing a messaging queue or designing a rate limiter as well as designing popular real world systems like WhatsApp, YouTube, Udemy, or Amazon.  

You can practice them to build your system design skills slowly, one by one 

At the end of the article, I will also share a System design template which you can use to answer most of these question in a structured manner, very useful for interviews as it allows you to cover key details in a limited time during interview 

1. System Design Basics Interview Questions

We will start with interview questions which test your knowledge about System design basic concepts like scalability and failover, important software architecture components like messaging queue, API gateway, load balancer, caching and CDS, Cloud computing platform like AWS and Azure etc.

Wherever possible I have also linked to the answer and solution for your reference but for System design problem, you can find most of the solutions on these System design YouTube Channels which I have shared earlier 

Key to answer these questions is solid knowledge of System design basics and topics so you must spend some times to prepare those topics. 

1. Difference between JWT, OAuth, and SAML? (answer)
2. Reverse Proxy and Forward Proxy? (answer)
3. Horizontal scaling and vertical scaling? (answer)
4. Microservices and Monolithic architecture? (Answer)
5. Vertical and horizontal partitioning ? (answer)
6. What is Rate Limiter? How does it work? (answer)
7. How does Single Sign On (SSO) works? (answer)
8. How does Apache Kafka works? why it so fast? (answer)
9. Difference between Kafka, ActiveMQ, and RabbitMQ? (answer)
10. API Gateway vs Load Balancer? [solution] 

and, here is a nice diagram which highlights the difference between API Gateway and Load Balancer. 

2. Easy System Design Problems for Interviews

Now let's see a easy System design problems you can start practicing for interviews. These are often involve creating a software architecture components like designing a rate limiter or messaging queue or bounded buffer or solving popular questions like URL shortening etc

They key to solve these questions is to present the requirement you know and then get the confirmation from the interviewer, instead of asking interviewers which features should I implement. For example, when you design a messaging queue, you can start with basics publish-subscribe functionality first before going for multiple consumers, partitioning etc. 

11. How do you design a bounded buffer? (solution)
12. How to Design Text Storage Service like Pastebin? [solution]
13. Design Content Delivery Network (CDN) ? [solution]
14. Design Parking Garage [solution]
15. Design Vending Machine [solution]
16. How to Design Distributed Key-Value Store
17. Design Distributed Cache
18. Design Distributed Job Scheduler
19. How to Design Authentication System

20. How do design a thread pool like Java's Executor Framework?
21. How to Design URL Shortener like TinyURL [solution]

And, here is a high-level design of creating a URL shortner like bit.ly or TinyURL or goo.gl

3. Medium and Hard System Design Interview Questions

Now that we have seen both theory based questions and easy questions, not let's see the real System design question from interviews where you will be asked to design a popular App like WhatsApp, YouTube etc. 

22. How to Design Tinder
23. Design WhatsApp (solution)
24. How to Design Facebook
25. Design Twitter or X?

26. Design Reddit
27. Design Netflix [solution]
28. Design YouTube [solution]
29. Design Google Search
30. Design E-commerce Store like Amazon
31. Design an Analytics Platform (Metrics & Logging)
32. Design Notification Service
33. Design Payment System
34. How to Design Location Based Service like Yelp
35. Design Uber
36. Design Food Delivery App like Doordash
37. Design Google Docs
38. How to Design Google Maps
39. Design Zoom
40. How to Design File Sharing System like Dropbox
41. How to Design Ticket Booking System like BookMyShow
42. Design Distributed Web Crawler
43. How to Design Code Deployment System
44. Design Distributed Cloud Storage like S3
45. How to Design Distributed Locking Service
46. Design Rate Limiter
47. Design Distributed Message Queue like Kafka
48. Design Flight Booking System
49. Design Online Code Editor
50. Design Stock Exchange System
51. Design Spotify
52. Design TikTok
53. Design Shopify
54. Design Airbnb
55. Design Autocomplete for Search Engines
56. How to Design Unified Payments Interface (UPI)
57. Design Instagram [solution]
58. How do you design a crossing engine? or trade matching engine? (solution)
59. How do you design a trade aggregator or portfolio manager? (solution)

60. Design Flipcart (Solution)

And, as promised, here is a nice System Design Interview Question template you can follow to answer any System design problem on interviews. This template provides a structure which you can use to articulate your answer and mention key software architecture components like API Gateway, Load Balancer, Caches, Messaging Queue etc. 

That's all about the 100+ System Design Interview Questions and Problems you can proactive for your next Software Engineering interviews. These questions not only cover key System design topics like horizontal and vertical scalability, forward vs reverse proxy and monolithic vs microservices but also has many easy, medium and hard system design problems you can solve to become an expert Software developer and architect.


As I said in the first paragraph, I intend to collect and share 100+ System design questions and right now I only have 60 questions, so stay tuned and bookmark the page, I will be keep adding new question into this list.


If you come across any System Design question on interview which is not in this list or asked to you, feel free to share with us in comments.


Other System Design Tutorials and Resources you may like

• How to Prepare for System Design Interview in 2024
• Is ByteByteGo really worth the hype?
• Top 5 Places to learn System design and Software design
• Is DesignGuru's System Design Course worth it
• The Complete Java Developer RoadMap
• Is Exponent's System Design Course worth it?
• 10 Best Places to Learn System Design in 2024
• My Favorite Software Design Courses for 2024
• 3 Places to Practice System Design Mock interviews
• 20 System Design Interview Questions for Practice
• Is Designing Data intensive application book worth reading?

All the best for your System Design Interviews, if you have any doubt or questions, feel free to ask in comments.