System design interview question
Design Car Rental System
A low-level design for a car rental system covering a vehicle type hierarchy (Car/Truck/SUV), date-range availability checking, a pricing model (daily rate + extras + late return fees), a reservation state machine (PENDING → ACTIVE → COMPLETED / CANCELLED), damage reporting with cost assessment, and mileage tracking. Demonstrates Factory pattern for vehicle creation, Strategy for pricing, and State machine for reservation lifecycle.
Practice this question step by step with an AI interviewer that reviews your requirements, your architecture and your trade-offs, and scores the design.