Design a Cross-Border Ride-Sharing System

Problem Statement: Cross-Border Ride-Sharing

A cross-border ride-sharing system handles trips that begin in one jurisdiction and end in another — a taxi from Geneva to France, a ride from Singapore to Malaysia. The matching and navigation look like ordinary ride-hailing; the hard part is that the moment a trip crosses a border, a second country's laws, currency, taxes, and licensing attach to it. The system must get all of that right, automatically, for a rider who just wants to go somewhere.

The defining concept is the jurisdiction: a region with its own rules — currency, VAT/tax rate, surge-price caps, what driver licenses are valid, and where rider data may legally be stored. Every trip is governed by one or more jurisdictions, and a cross-border trip is governed by several at once, sometimes split by the distance traveled in each. So the core of the system is not the map; it is a jurisdiction-aware rules and settlement engine that resolves which rules apply, prices and taxes correctly per region, verifies the driver may legally operate, and settles revenue across currencies and tax authorities.

The consequence is that this is mostly a correctness and compliance system. A mispriced fare annoys a customer; a tax remitted to the wrong government, or a driver operating without a valid cross-border license, is a legal and financial liability. Three problems define it: rule resolution (which jurisdiction(s) govern this trip and segment), compliant pricing + tax (correct currency, VAT, surge cap per region), and multi-currency settlement (split fare and tax across jurisdictions with correct FX).

The scale that matters is not raw volume — cross-border trips are a small fraction (~1%) of a platform's ~10 million rides/day, so ~100,000 cross-border rides/day (~1–2/s). The challenge is per-trip correctness across a matrix of jurisdictions and currencies, and keeping that rule matrix current as laws change — a compliance engine wearing a ride-hailing costume.