Tasonic is an international mobile top-up platform. Customers send airtime and data to phones anywhere in the world, usually to family.
The transaction looks simple from the outside. Underneath it sits a system of mobile operators, international suppliers, payment rails, fraud prevention, APIs, mobile applications and transaction monitoring, all of which have to agree before a top-up lands.
Building it meant working across nearly every part of a modern digital product: engineering, risk, customer support and international operations. Every carrier has its own idea of what a valid phone number looks like, and reconciling those is more of the work than anyone expects.
It now reaches more than 620 operator networks across 150-plus countries, with delivery usually inside a few seconds, and runs on the web plus iOS and Android apps.