Fly's modern, global TLS stack makes applications faster by getting closer to users. When a TLS connection is made, it involves a handshake between server and client. The further away the client, the longer the process takes. By handling TLS termination "at the edge", Fly handles that handshake in the nearest datacenter to the user, reducing connection time by hundreds of milliseconds.
Fly's global TLS stack also supports modern ECDSA certificates for browsers that understand them. You can attach as many certificates to your Fly application as you need, from one certificate to a million certificates, Fly can handle it.