Expert
Fail over in seconds, not minutes
A Paris neobank promises 99.95 % availability. It runs active-passive between Paris and Frankfurt with DNS failover, and its ledger already replicates across three regions. At 15:00 Paris goes down for two hours. Keep the promise.
Over one day, 99.95 % leaves less than a minute of full outage at peak traffic. The DNS TTL is already down to 60 seconds. A global load balancer health-checks the endpoints it points at, so aim it at the application fleets themselves.
What your design must achieve
- Availability ≥ 99.95 %
- Latency p99 < 300 ms
- Monthly bill < 15,000 $ bonus