Cloud platforms distribute workloads across Availability Zones (AZs) by default, for resilience. But cross-AZ traffic, replicated storage, and unnecessary spread of stateless and stateful workloads generate ongoing charges.
For platforms that don’t need a strict multi-AZ SLA, intentionally co-locating an application’s compute and its stateful components
not just the database, but any StatefulSet: message queues, search indices, caches, custom stateful services — inside one AZ can reduce infrastructure costs by more than 10%, depending on internal traffic volume and architecture.
Where the cost comes from
Cross-AZ charges typically originate from:
