Digital lenders, mobile money operators, microfinance institutions, and insurers operating across Africa, Southeast Asia and other global markets share a common communication challenge: their customers are not a uniform population. Some have smartphones and mobile data. Many use feature phones. Some are in areas with consistent network coverage. Others are not. Building a customer communication system that reaches all of them, reliably, at scale, across multiple products and markets, requires different decisions than a communication setup built for a connected, smartphone-first customer base..