What It Actually Takes to Run a Cross-Border Marketplace: Six Years of Shpper

Shpper is a personal-shopping marketplace that facilitates cross-border transactions. The platform connects buyers and travellers, who are already flying the same routes with empty luggage space. As the CTO, I am in charge of the entire platform, from the Flutter apps for both sides to the backend, payments, escrow, identity verification, and the release pipeline. We are currently on version 14.2.0, with a rating of 4.64 on the App Store from 72 ratings.

Running a two-sided marketplace like Shpper is far more complex than expected. The app consists of two products with opposing interests: the buyer wants a cheap, quick, and reliable delivery, while the traveller wants to be paid well, with minimal risk, and without blame for customs. Designing features from two perspectives and considering the shared middle, such as requests, offers, and trips, is essential. Any change to the shared middle requires simultaneous updates to both apps, extending the release cadence.

Trust between strangers is the actual product of Shpper. The platform holds money from the moment a deal is struck until the item is confirmed delivered, making escrow the primary trust mechanism. Identity verification is crucial to ensure that the funds are protected if there's a problem. The state machine, which governs the transitions from request to delivery, is the core product, with numerous potential failure points that need well-defined responses.

Money-moving operations must be idempotent, atomic, and append-only to prevent issues. Cross-border transactions introduce additional challenges like fluctuating prices, customs duties, and restrictions on certain items. The engineering team must design for instability, as timelines slip, prices change, and routes vanish. As CTO, my role extends beyond architecture to encompass business decisions, such as handling delivery issues, determining policies, absorbing costs, and communicating with users.

Ultimately, owning Shpper end-to-end means understanding both the engineering and business aspects of the platform. I am responsible for the state machine, the commercial consequences, and choosing what not to build, as the market has an infinite backlog.