Every design decision costs kilobytes and cognitive load. What we learned building interfaces for users who may never load a full webpage.
Design Constraints as Design Direction
A USSD menu gives you roughly 182 characters and a numeric keypad. There's no color, no imagery, no whitespace to lean on. Every word has to earn its place, and every flow has to be short enough to complete before a session times out.
That constraint turned out to be clarifying rather than limiting. It forced us to define the actual decision a farmer needs to make at each step — book, confirm, pay — and strip everything else away. Those same flows, once proven at their most constrained, translate cleanly into the richer mobile and web experiences built for service providers and Field Agents.