About System Design Interviews
If you’re a mid-level or senior-level software engineer, regardless of where you interview, you will get asked at least a few system design questions. Most companies will ask system design questions during the onsite, but some may include a system design component in their technical phone screen (more likely if they’re a startup rather than a FAANG).
System design interview questions fall, by and large, into the following 12 categories:
- APIs
- Databases (SQL vs NoSQL)
- Scaling
- CAP theorem
- Web authentication and basic security
- Load balancers
- Caching
- Message queues
- Indexing
- Failovers
- Replication
- Consistent hashing
That’s a long list, and system design is a really broad topic. Rather than trying to summarize everything you need to know about these types of interviews in a few paragraphs (an impossible task), we’ve written the best guide to system design interviews out there.
By the way, many people believe that in order to pass a FAANG system design interview, you have to have professional experience with distributed systems. We’ll show you that that’s categorically false, and that with the right preparation, you don’t need to fall into the catch-22 of having to have worked at a FAANG in order to get a job at a FAANG.
Check out our in-depth guide to system design, developed by the best interviewers in the industry, directly from their experience in thousands of technical interviews:
System Design Interview Replays
System Design Interview Questions and Solutions
Distributed Databases
How would you organize a SQL database like MySQL such that you can add more machines once your current ones reach maximum capacity? With the limitation that you do not have access to any automated tools for distributing.
Image Filter Service
Create a service that allows users to upload an image and apply filters and then sends users a link to download their filtered image.
Design LeetCode
Design a coding competition platform with a leaderboard and execution environment.
Design a Free Food App
Design the service for an app that supports distributing 6 million burgers in 10 minutes.
File Parsing
Given an inefficient file structure, how would you store data to efficiently look up the query? How would you alter this if you had many computers available?
Design WhatsApp
Design a message app system and client (e.g. WhatsApp) supporting a list of requirements.

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