Migrating the American Express Payment Network, Twice

https://americanexpress.io/migrating-the-payments-network-twice/

Migrating the Payments Network Twice with Zero Downtime

The architecture and coordination that kept global transactions flowing through complex application and infrastructure changes.

American Express Technology

Re: transition to micro services (from monolith).

I’m surprised a network so sensitive to latency (as are payment networks), was able to achieve their latency SLAs with micro services.

Maybe Amex being a closed-loop network helps with latency?