Problem Description
Design a restaurant reservation system, similar to common booking platforms, that facilitates both customer and restaurant operations.
The system must allow customers to search for availability and book tables at various restaurants, while also enabling restaurants to efficiently manage their tables and reservations.
Core Requirements
Customer-Facing Features
- Availability Search: Customers must be able to view a restaurant’s availability for a specified date, time, and party size.
- Reservation Management:
- Create new reservations, providing details such as name, contact information, party size, desired time, and any special notes.
- Modify existing reservations.
- Cancel existing reservations.
- Notifications: Receive confirmations and reminders via email, SMS, or push notifications.
Restaurant-Facing Features
- Restaurant Configuration:
- Perform CRUD (Create, Read, Update, Delete) operations on restaurant profiles, including operating hours and blackout dates/holidays.
- Configure table inventory, specifying table IDs, capacities, and identifying combinable tables.
- Reservation Oversight:
- View upcoming reservations.
- Mark reservations as "no-show," "seated," or "completed."
Non-Functional Requirements
- Correctness: Absolutely prevent double-booking of tables. This is critical.
- Low Latency: Availability lookups should have low latency (e.g., p95 < 200–300ms).
- Scalability: The system must handle traffic spikes, particularly during peak lunch/dinner hours or for popular restaurants.
- Auditability: All changes and cancellations must be auditable (who changed what, when).
- Idempotency: APIs should be idempotent where appropriate.
Assumptions
- Multi-Restaurant Platform: The system will support multiple restaurants.
- Time-Bound Reservations: Reservations have a default duration (e.g., 90 minutes), which should be configurable per restaurant.
- Timezone-Aware Scheduling: The system must correctly handle scheduling across different timezones.
Design Considerations
Candidates should cover the following aspects in their design:
- Data Model: Propose a data model for tables, reservations, locks, and time slots.
- APIs and Main Flows: Define the key APIs and outline the primary user flows (e.g., search availability → book → confirm → remind).
- Concurrency Control: Detail the strategy to prevent double-booking.
- Scaling and Caching: Describe the approach to scaling the system and the caching strategy.
- Edge Cases: Address how the system handles cancellations, no-shows, walk-ins, table combinations, and potential overbooking/waitlist scenarios.
AI interview prep
Core dilemma
Balancing strong consistency for reservations (preventing double-booking) against low latency for availability lookups under high concurrency and traffic spikes, while managing complex scheduling logic (time-bound, combinable tables, timezones).
3 tradeoffs and 3 stress tests locked
Interview prep
Unlock the interviewer X-Ray rubric, tradeoff matrix, stress tests, clarifying questions, and key concepts.
Problem Description
Design a restaurant reservation system, similar to common booking platforms, that facilitates both customer and restaurant operations.
The system must allow customers to search for availability and book tables at various restaurants, while also enabling restaurants to efficiently manage their tables and reservations.
Core Requirements
Customer-Facing Features
- Availability Search: Customers must be able to view a restaurant’s availability for a specified date, time, and party size.
- Reservation Management:
- Create new reservations, providing details such as name, contact information, party size, desired time, and any special notes.
- Modify existing reservations.
- Cancel existing reservations.
- Notifications: Receive confirmations and reminders via email, SMS, or push notifications.
Restaurant-Facing Features
- Restaurant Configuration:
- Perform CRUD (Create, Read, Update, Delete) operations on restaurant profiles, including operating hours and blackout dates/holidays.
- Configure table inventory, specifying table IDs, capacities, and identifying combinable tables.
- Reservation Oversight:
- View upcoming reservations.
- Mark reservations as "no-show," "seated," or "completed."
Non-Functional Requirements
- Correctness: Absolutely prevent double-booking of tables. This is critical.
- Low Latency: Availability lookups should have low latency (e.g., p95 < 200–300ms).
- Scalability: The system must handle traffic spikes, particularly during peak lunch/dinner hours or for popular restaurants.
- Auditability: All changes and cancellations must be auditable (who changed what, when).
- Idempotency: APIs should be idempotent where appropriate.
Assumptions
- Multi-Restaurant Platform: The system will support multiple restaurants.
- Time-Bound Reservations: Reservations have a default duration (e.g., 90 minutes), which should be configurable per restaurant.
- Timezone-Aware Scheduling: The system must correctly handle scheduling across different timezones.
Design Considerations
Candidates should cover the following aspects in their design:
- Data Model: Propose a data model for tables, reservations, locks, and time slots.
- APIs and Main Flows: Define the key APIs and outline the primary user flows (e.g., search availability → book → confirm → remind).
- Concurrency Control: Detail the strategy to prevent double-booking.
- Scaling and Caching: Describe the approach to scaling the system and the caching strategy.
- Edge Cases: Address how the system handles cancellations, no-shows, walk-ins, table combinations, and potential overbooking/waitlist scenarios.