Virtually every start-up dreams of becoming a platform at some stage. After all, it is the most powerful position in the ecosystem. What has been the one rule to becoming a platform? Develop a killer app that gets you to scale: and then open up the platform once your reach is attractive enough for other developers to develop specific apps for your platform. This game plan has worked for consumer (Facebook, Twitter) and enterprise (Salesforce, Shopify) apps alike.

But recently, we have seen a new breed of platform emerging: platforms that are targeted at developers. Their mission is simple: solve the pain of integrating all the cumbersome and fragmented legacy systems, by providing an easy-to-integrate-with and easy-to-manage frontend for developers.

For example, we see horizontal platforms like Twilio that replaces all the telecom hardware with an API for phone, VoIP, and messaging. There’s Stripe and Braintree for payment processing, and Lob for printing. This is what Garry Tan has called the API-ization of everything: “Where there is paper to push, a call to answer, or a purchase to approve, there is an API coming to replace it.”

In addition to these horizontal platforms, there are also very interesting vertical players emerging: Spout for finance, Rets.ly for real estate, and Clever for education. While horizontal developer platforms are usually built around features, vertical platforms are usually built around data.

The traditional platform approach (i.e. Facebook, Salesforce) is still alive and well, but it feels like we are on the cusp of tremendous innovation in the field of developer platforms as the web is evolving into being entirely programmable.