In a Platform as a Service environment such as Scalingo, public routing refers to the way hosted applications are exposed to the Internet through publicly accessible network paths.

It designates how the platform connects external (Internet) traffic to the right application running inside our managed infrastructure. This process is fully handled by Scalingo in an automatic, fast, and secure manner.

When an application is deployed on Scalingo, the following happens:

• The platform runs your app on our internal infrastructure, in an isolated runtime environment.
• It assigns your application a publicly reachable domain name, ending in .scalingo.io..
• It updates our public routing layer to ensure incoming requests are forwarded to the appropriate application containers. It ensures the connection between the outside world and our internal runtime environment (where your application is running).
• The public routing layer also handles TLS termination (HTTPS), load balancing, rate-limiting, and automatic failover.

In short, public routing turns your isolated application instance into a publicly consumable service. Networking (DNS, requests forwarding), security (TLS termination), and scalability (rate-limiting, failover) concerns are all automatically handled by the platform.

Public routing is a core component of a PaaS. It brings a good part of the magic while sparing our customers a lot of networking annoyances. As such, it’s fully included into our offers.