System requirements


Functional:

  1. create tiny url and redirect for original url
  2. allow user to customiz tiny url
  3. delete tiny url
  4. update tiny url
  5. epxire date



Non-Functional:

List non-functional requirements for the system...

  1. high available
  2. scable
  3. low latency
  4. high reliable -> not lose user data
  5. read heavily system


Capacity estimation

  1. Data storage
  2. 1M tiny url generated
  3. Original url size: 100 char. 200 byte
  4. tiny url: 30 char -> 60 byte
  5. each url: 300 bytes
  6. all storage ->
  7. 300 * 1M = 300 MB data storage
  8. TPS
  9. read - write ratio = 5:1
  10. write
  11. DAU: 1M
  12. 1M read per day -> (100K second/day) = 10 TPS
  13. write 2TPS:
  14. traffic distributed evenly





API design

Define what APIs are expected from the system...


POST

/v1/createTinyURL

(user_token, original_url, customized_url(optional), expire_date)


GET

/v1/redirectURL

(user_token, tiny_url)


DELETE

/v1/deleteURL

(user_token, tiny_url)



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...


no relation needed

recommend NoSQL database example (dynamoDB)



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...






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?