Infobip.
The biggest platform you've never heard of, but have likely used. Infobip is a global SMS enterprise platform that sends literally billions of messages for clients including Facebook, Uber, Netflix, eBay, and WhatsApp. The company started as a networked distributor of SMS, providing an API to create and send messages. We designed, from scratch, their first web-portal to allow customers to create and send rich, conditional campaigns to service SMS, voice, email, and push. After launch, in the first month alone users sent 15 million messages. End-to-end, from functional specs to user stories to whiteboard flows to prototypes and design, this international product continues to grow and lead in its industry.