System requirements


Functional:

  • keep track of amount of vehicles in parking lot
  • keep track of special vehicles (electric/disabled) in parking lot
  • register license plate of entering vehicles
  • track time in parking lot for each license plate
  • manage payments on basis of license plate
  • open exit gate for vehicles with license plate which is paid for



Non-Functional:

  • payment service should have a very high availability
  • visitors should have ample time to exit the parking garage
  • system should be able to handle hundreds of visitors entering, paying or leaving within the same hour




Capacity estimation

  • 400 spots





API design

  • get available spots
  • enter parking lot with a license plate
  • checkout
  • leave parking lot with a license plate





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?