A single server and a database is enough here
Ten years ago a system design conversation was short. A server, a monolith, Postgres, maybe a load balancer in front. For most products that was the entire architecture, and it held. Now the same conversation opens with API gateways and doesn’t stop: Kubernetes, service meshes, Kafka, Redis, three databases because each one is good at one thing, gRPC, GraphQL, Elasticsearch, Terraform, Prometheus, tracing, sharding, replication, autoscaling. The awkward part is that none of it is junk. Every one of those tools exists because someone hit a real wall: more users, more data, more teams, more regions, more nines of uptime. ...