The Top K Problem (Heavy Hitters) is a common type of dashboard. Based on the popularity or lack…

Design a news feed that provides a user with a list of news items, sorted…

The question is to design a service for landlords to rent rooms for short-term stays to…

Let’s design a text messaging app, a system for 100K users to send messages to…

A CDN (Content Distribution Network) is a cost-effective and geographically distributed file storage service that is…

We design an image sharing service like Flickr. Besides sharing files/images, users can also append…