A user in Frankfurt hitting an API hosted in us-central1 pays a fixed tax: roughly 90–110 ms of round-trip time before a single byte of application logic runs. Add TLS handshake and you have burned 300 ms before your handler is invoked. No amount of code optimization fixes the speed of light.

Google Cloud's global external Application Load Balancer solves part of this problem by terminating the connection at the closest of ~190 Google Front End (GFE) points of presence, then carrying the request over Google's private backbone to the nearest healthy backend.…