Design a multi-carrier parcel delivery system
Company: Walmart Labs
Role: Software Engineer
Category: System Design
Difficulty: medium
Interview Round: Technical Screen
Design a system for shipping customer parcels that supports multiple delivery partners/carriers (e.g., UPS, USPS, FedEx).
Your system should enable an e-commerce platform (or warehouse) to:
- Create a shipment for an order (addresses, package details).
- Choose or be assigned a carrier and service level.
- Purchase shipping / generate a label.
- Track shipment status through delivery.
- Handle carrier-specific differences while providing a unified internal API.
Include key APIs, data model, main components, integrations with carriers, and how you ensure reliability and scalability.
Overview: This question evaluates system design and integration competencies, including distributed architecture, API design, data modeling, reliability, scalability, and handling heterogeneous third-party carrier integrations for a multi-carrier parcel shipping platform.