What is ACME?
ACME is the protocol Let’s Encrypt uses to issue DV certificates without a human in the loop.
The idea
An ACME client proves control of a hostname, then the CA signs a certificate. sslcertificates.io is that client for your organization.
Why not run it yourself
You can, and many teams do. The platform exists when you want inventory, webhooks, and multi-app access without each service speaking ACME.