Heroku is a cloud-based platform for web applications. It aims to allow developers to focus on applications rather than infrastructure. It provides a low-friction workflow for deploying a new application quickly, while also supporting long-term scalability. It also offers a marketplace of add-on services, such as databases and monitoring.

There are several similar services to Heroku, some of which we will cover later in this chapter. Heroku was one of the first services of its kind. In particular, it was one of the first to support Node.js as a first-class citizen. It also offers many features for free, including everything needed for the worked example in this section.