What:
The progressive architectural roadmap to expand a software system from a single server container to a distributed microservice network.
Primary purpose:
Preventing resource exhaustion, server downtime, and write/read chokepoints under scaling workloads.
Usually used for:
Scaffolding high-level design structures, justifying scalability, and proving architecture maturity.
How should I think about this inside system architectures?
📦 Separate App & DB
First step of scaling: move the database off the application server to its own dedicated node with optimized disk I/O.
🧱 Go Stateless First
Store user sessions inside Redis rather than server memory. This lets you boot up/kill application nodes dynamically behind a load balancer.
🔪 Shard the Writes
Caches and read replicas scale reads indefinitely, but scaling high-volume writes eventually requires sharding primary tables across nodes.