This case study looks at the strategies employed by WePay that has helped the organization generate month-on-month growth in developer engagement and in the creation of new products, services and processes that rely on WePay’s API.WePay is a payment processing company for platforms, crowdfunding, marketplaces and business software. After pivoting to focus more on platform businesses as its customer base, WePay grew its API at a rate of 600% in 2014, when measured by visits to their API-as-a-product website.Key to WePay’s success has been a refresh of its developer portal to refine messaging to suit the more strategic focus of working with platform-oriented businesses. New tools have helped walk startups through the process of establishing a platform-based business and monetizing it by using the WePay API. By situating its API in the wider context of platform businesses–and by providing a full suite of developer resources including code samples and step-by-step tutorials–WePay has been able to support the growth of its customers’ businesses. This, in turn, supports WePay’s own business model, which is based on a transaction fee.WePay has utilized a range of developer engagement strategies in order to achieve its phenomenal growth and continue to gain traction in its identified market. It will be important to watch how the organization has maintained the relationships it has built with platform businesses and developer teams in an increasingly competitive payments space.