Presented at ServerlessConf NYC2016. The [webtask.io](https://webtask.io) microservice platform has been created and is used internally at [Auth0](https://auth0.com) to support multi-tenant SaaS extensibility through custom code, in cloud and on-premise. In this talk I will describe our journey from the driving scenario, the choice of a "better web hook" paradigm to address it, the architecture and design decisions we've made along with the mistakes and changes the system has undergone. I will also provide an insight into a security model that makes webtask.io platform uniquely suited to be used directly over HTTP from HTML5 or mobile apps. Docker, Node, ZeroMQ, Mongo, and more.