Loading...
List functional requirements for the system (Ask the chat bot for hints if stuck.)...
Should shorten a URL given
custom URL
Redirect from short to long URL
Analytics for user
List non-functional requirements for the system...
high availability
high consistency
scales well
low latency
Estimate the scale of the system you are going to design...
Each link will require a short URL, the long URL, and an expiration date. 300 bytes per link
Define what APIs are expected from the system...
API from client facing application which creates websites to database which stores the links.
GET api to database when you type in a short URL to redirect to a long one
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...
Database has an index which is the short URL. It can use this to quickly get the long URL by the index.
Each short URL must be unique. If custom URL is requested by consumer, will query database to see if taken. If not, add it to the database. If the user is not specifying custom URL, just give them a unique short link which is like tinyurl_{row_number_in_data}.
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...
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...
User making URL:
they use a free random URL, the database finds which row is the next one, and returns that index for the short URL index and value.
if they pay for a custom URL, the URL will then have whatever they want in it. Lookups can be done with B trees then for O(log n) time. POST requests.
typing in a tinyURL:
user googled a tinyURL link. The result is the database is queried GET with that link. Then the user is redirected.
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...
One component is the server that does the computations. It scales very easily as it is just asking the database how many rows it has and adding one to that.
Explain any trade offs you have made and why you made certain tech choices...
Try to discuss as many failure scenarios/bottlenecks as possible.
What are some future improvements you would make? How would you mitigate the failure scenario(s) you described above?