Uber·Software Engineer·Onsite - System Design / Architecture·Staff

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Apr 2026

Summary

System design round at Uber for an EM role, focused entirely on cart management for Uber Eats. The prompt was deliberately open-ended and you were expected to drive the requirements gathering yourself, which I wasn't fully prepared for.

Questions Asked (1)

Design the backend for Uber Eats cart management, covering the full lifecycle from cart creation through order fulfillment. The prompt is intentionally vague. You're expected to drive requirements gathering yourself.

System DesignData ModelingTechnical Trade-offs

Author's notes

I spent way too long waiting for the interviewer to narrow the scope.

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AI HintsAI Generated

Suggested Approach

Start by clarifying requirements and scope, then propose a high-level design covering cart lifecycle, data model, and key services. Focus on trade-offs and scalability, and iterate based on interviewer feedback.

Pro tip: Demonstrate proactive requirement gathering by asking about scale, consistency needs, and integration points; this shows you can drive ambiguous problems like a senior engineer.

1. Clarify Requirements

Ask questions to understand functional and non-functional requirements, such as user scale, cart persistence, order flow, and consistency guarantees.

2. High-Level Design

Outline the main components (e.g., API gateway, cart service, order service, database) and their interactions, and sketch the cart lifecycle.

3. Data Modeling

Design the schema for carts, items, and orders, considering relationships, indexing, and storage choices (SQL vs NoSQL).

4. Deep Dive into Key Areas

Discuss scalability, consistency, and fault tolerance for critical parts like cart updates, checkout, and order fulfillment.

5. Trade-offs and Wrap-up

Summarize trade-offs made, potential bottlenecks, and future improvements, and invite feedback.

Key Points to Mention

Cart lifecycle states (active, checked out, abandoned) and transitions
Data consistency models (e.g., eventual vs strong consistency) for cart and order data
Scalability strategies (sharding, caching, read replicas) for high traffic
Idempotency and concurrency control for cart updates and checkout
Integration with external services (restaurant inventory, payment, delivery)
Monitoring, logging, and failure recovery mechanisms

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