High-Level Design (system design) rounds at Uber lean toward real, ride-hailing-and-marketplace-adjacent problems — expense settlement, location-based recommendations, and real-time geospatial pipelines — rather than generic textbook prompts. Interviewers reward a structured approach: requirements first, then data model, core algorithmic pieces (like debt simplification or geohashing), and scaling considerations, in that order.
Problem 1Design a Bill-Splitting & Expense Settlement System
Design a bill-splitting and expense-settlement system (like Splitwise) for groups of users, and reason about how it scales to a large number of concurrent group-expense entries.
- Cover a database schema for users, groups, expenses, and splits.
- Cover graph-based debt simplification — minimizing the number of settlement transactions between users.
- Cover how the design stays consistent under concurrent expense entries, and how it scales horizontally.