Once you have a good grip on the basics of system design, you should practice answering the most common question asked in system design interviews – “How would you design a system?”  

The kind of system you are asked to design depends on the company you are interviewing for. While Google System Design interview questions differ from Amazon System Design interview questions, you can still prepare a basic foundation, then research the company’s use cases. 

Below are some of the most common system design interview questions and how to answer them:

• How would you design a search engine? 

Define the overall architecture based on your knowledge of system design basics. Pay attention to keyword searches and where you want to place your crawler for indexing links that appear in a search. Calculate and analyze the number of links for each website. To avoid spam, check outbound links.

• How would you design a shared drive? 

Shared Drive questions are a good test of algorithm basics. Ask if the system will be working in real-time and if locking would be necessary. 

Focus on differential synchronization, that is, synchronizing two or more copies of a document in real-time. Use event-passing to allow real-time collaboration. 

• How would you design Twitter? 

Social networking platforms are a popular question in system design interviews. Pay attention to onboarding flow, user-follow flow, tweet flow, scalability, and read-to-write ratio. 

• How would you design a video streaming system?  

A video streaming system will need a recommendation service. It should also be able to read different formats. Focus on how you can simplify the process of onboarding new content since it is done regularly.

• How would you design a messaging system? 

Messaging systems like Whatsapp heavily depend on the right memory allocation. Also, brush up on HTTP, WebSocket, and long pooling. 

• How would you design a vaccine rollout system? 

Often, interviewers are keen to assess your capabilities in solving current world problems. 

In this case, key points to consider will be: creating unique IDs to prevent overlapping, a synchronized update system, a simplified user interface, and appropriate memory allocation. 

Additional use cases/question topics to prepare for your System Design interview are:

• Web Crawler 
• TinyURL System 
• Typeahead Suggestion Service – Autocomplete 
• API Rate Limiter 
• Social Media System – Facebook, Instagram, Twitter 
• Cloud Services – Google Drive, Google Docs, Amazon S3 
• Video Streaming – Netflix, Prime, Hulu 
• Online shopping – Amazon, Walmart, Airbnb, eBay 
• Transportation – Uber, Lyft 
• Mapping System – Google Maps 
• Video Conferencing – Zoom, Google Meet, Skype 
• Review System – Yelp, TripAdvisor, DoorDash 
• Dating Platforms – Tinder, Bumble, Hinge 
• Payment – PayPal 
• Gaming – Online Multiplayer  
• Ticket Management System – Entertainment, Hotels, Airlines 
• Library Management System