Designing Stateless Web Services for Horizontal Scaling
Horizontal scaling adds application replicas instead of making one machine larger. The load balancer can send each request to any healthy instance, which only works reliably when instances do not depend on unique local state.
“Stateless” does not mean the application has no state. It means durable or shared state lives outside an individual process so any replica can continue serving the workload.
Identify hidden local state A service may appear stateless while depending on:
