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Extend rules for trip-level aggregates and outputs

RipplingSoftware Engineer · Technical Screen
MediumSoftware EngineerTechnical ScreenSystem Design

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This interview question evaluates requirements, scale assumptions, API/data design, architecture, trade-offs, failure modes, and rollout in a realistic interview setting. A strong answer for Extend rules for trip-level aggregates and outputs states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

Extend the same system to support aggregate trip‑level rules. Implement handling for rules like: (

  1. A trip’s total expenses cannot exceed $2000; (
  2. Total meal expenses per trip cannot exceed $200. In the provided sample, trip "002" violates both rules. Update the design and the evaluateRules return type so the output includes per‑trip violations alongside per‑expense violations. Describe grouping/aggregation strategy, evaluation order, explainability for aggregates, performance considerations, and how these results integrate into the expenses API used by many companies.