System requirements
Functional:
- Users should be able to search through different garages for availaibility
- Users should be able to book slots for given days/times
- Different vehicle types: Compact, regular, big, motorcycle
- Should ideally use the car type as mentioned and map to correct parking, but can park in larger space as well if we have high availaibility
- Determine a rate, and integrate with a 3rd part solution to handle payments
Non-Functional:
- Not overbook (Can assume 10% max overbooking)
- Scalability
- Consistency > Availaibility
Capacity estimation
Estimate the scale of the system you are going to design...
1 garage has 10 floors, 100 parking per floor
Total 1000 parking per garage
10,000 Garages worldwide
total parking 10 Million
10 M users daily park once
API design
Define what APIs are expected from the system...
External APIs
GET /garage/loc={}lat&long -> returns closest garages
GET /garage/:garageId -> [parking space availaible per vehicle type]
POST /garage/:garageID/vehicleType&time={start&end} -> reservationId
POST /reservation/book/:reservationId -> Book
PUT /reservation/book/:reservationId/extendTime -> Rebook to extend
Database design
Garage Table
garageId PK
location
floors
spaces compact
spaces regular
..
Rate Table
garageId, vehicle Type, day, time -PK
rate per hour
booking table
reservationID PK
userId
date
time
vehicleType
spotTypeInventory
garageId
spotType
date
totalInventory
TotalReserved
spot
garageId
spotTypeId
floor
user table
userId
address
location
payment
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?