System requirements


Functional:

List functional requirements for the system (Ask the chat bot for hints if stuck.)...

  • Users can post either binary or string contents to the service and get the unique URL back.
  • Users can share the content with others with he unique URL.
  • Users can assign tags and TTL to the content.Other can only read this.
  • Users can change the saved content.



Non-Functional:

List non-functional requirements for the system...

  • The service should be high-availably and high-reliable.
  • The service should be scalable to load and can process high user peaks.
  • If users post their content, it may be visible in some 100 milliseconds.
  • Only the registered users may post contents, but everyone can read it.






Capacity estimation

Estimate the scale of the system you are going to design...

Let's suppose the users may post 1 Mbytes and DAU is 1 Million users.

The service would be read-heavy, let's count that every user reads the post five times a day and posts new content daily. So it needs to store 730 Terabytes every 1 year ( it counts the data duplication) and 3,6 Petabytes for 5 years.

It needs 5 Terabytes of bandwidth to guarantee the read for 1 Million users.



API design

Define what APIs are expected from the system...


post(apiKey, userId, content,contentLength, tags,TTL) posts the content to the backend and returns the unique key and URL, passing of the content and its length and optional tags and TTL of contents. The use of apiKey guarantees the prevention of abuse of the service.


getPost(apiKey, URL, tags) requests the contact by URL and tags and returns it. The use of apiKey guarantees the prevention of abuse of the service.


deletePost(apiKey,userId, URL) delete the posted content from the service. The use of apiKey guarantees the prevention of abuse of the service.





Database design

Defining the system data model early on will clarify how data will flow among different components of the system. Also you could draw an ER diagram using the diagramming tool to enhance your design...






High-level design

You should identify enough components that are needed to solve the actual problem from end to end. Also remember to draw a block diagram using the diagramming tool to augment your design. If you are unfamiliar with the tool, you can simply describe your design to the chat bot and ask it to generate a starter diagram for you to modify...






Request flows

Explain how the request flows from end to end in your high level design. Also you could draw a sequence diagram using the diagramming tool to enhance your explanation...






Detailed component design

Dig deeper into 2-3 components and explain in detail how they work. For example, how well does each component scale? Any relevant algorithm or data structure you like to use for a component? Also you could draw a diagram using the diagramming tool to enhance your design...






Trade offs/Tech choices

Explain any trade offs you have made and why you made certain tech choices...






Failure scenarios/bottlenecks

Try to discuss as many failure scenarios/bottlenecks as possible.






Future improvements

What are some future improvements you would make? How would you mitigate the failure scenario(s) you described above?