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Amazon·Software Engineer·Onsite - System Design / Architecture·Senior

Senior
May 2026

Summary

Amazon solutions architect interview with a database design question. Pretty open-ended, which I wasn't fully prepared for.

Questions Asked (1)

Q1

Design a database schema for a pizza ordering system.

Data ModelingSystem DesignTechnical Trade-offs
Author's notes

Spent the first few minutes just listing entities out loud: customers, orders, pizzas, toppings, delivery addresses.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the scope and requirements of the pizza ordering system, such as whether it's for a single restaurant or a marketplace, and what features are needed. Then, design a normalized schema that captures core entities like customers, orders, pizzas, and toppings, while considering scalability and performance. Finally, discuss trade-offs and potential optimizations, such as denormalization for read-heavy workloads.

Pro tip: Demonstrate awareness of Amazon's leadership principles by emphasizing customer obsession (e.g., ensuring the schema supports a smooth ordering experience) and diving deep into edge cases like order modifications or refunds.

1. Clarify Requirements

Ask questions to understand the system's scope, expected scale, and key features (e.g., custom pizzas, multiple locations, delivery). This ensures the schema meets actual needs.

2. Identify Core Entities

List the main entities such as Customer, Order, Pizza, Topping, and Store. Define their attributes and relationships to form the basis of the schema.

3. Design Tables and Relationships

Create normalized tables with primary and foreign keys, using junction tables for many-to-many relationships (e.g., OrderItems, PizzaToppings). Consider using surrogate keys for simplicity.

4. Address Scalability and Performance

Discuss indexing strategies, partitioning, and potential denormalization for read-heavy operations. Consider how the schema supports high throughput and low latency.

5. Discuss Trade-offs and Extensions

Talk about trade-offs between normalization and performance, and how the schema can evolve to support new features like promotions or ratings.

Key Points to Mention

  • Normalization vs. denormalization: explain why you chose a particular level and its impact on performance and maintainability.
  • Indexing: identify columns that need indexes (e.g., foreign keys, order date) to speed up queries.
  • Scalability: consider how the schema handles growth in users, orders, and menu items, and whether sharding or partitioning is needed.
  • Data integrity: use constraints, foreign keys, and transactions to ensure consistency, especially for order placement.
  • Flexibility: design to accommodate customizations (e.g., half-and-half pizzas, extra toppings) without major schema changes.
  • Amazon-specific: mention how the schema supports Amazon's scale and customer obsession, and consider using AWS services like DynamoDB if NoSQL is appropriate.

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.