System Design Example — Parking Lot System

Overview

• Existing System: None (build from scratch)
• Daily Active Users: 1 million
• Client Apps: Web, Android, iOS
• Features:
  1. Browse parking spaces by country, city, location, floor
  2. View and book spaces
  3. Manage profile, settings, payments, notifications

Architecture Decisions

• Data Storage:
  • RDBMS → Parking data
  • NoSQL → User data (encrypted)
• Network Protocol: HTTPS
• Integrations: Push notifications, Payment Gateway
• CDN: For fast, location-based data delivery
• Services:
  • Monolithic → User & settings
  • Microservices → Parking space browsing
• Load Balancer: For high-traffic endpoints

Entity Design

Key Entities:

• Vehicle (Car, Bus, Truck)
• ParkingSpot (Small, Medium, Large)
• ParkingAdmin, ParkingOperator
• ParkingBuilding, Floor, Location, Area, City, Country
• ParkingFare, ParkingVehicleDriver

Data Sources:

• Driver: Registration and booking data
• Admin: Parking space inventory and configuration data

To Be Continued…