Many/most backends are stateless... In a way, they push the complexity of distributed systems to the db. They don't deal with sharding, load balancing, request

Many/most backends are stateless... In a way, they push the complexity of distributed systems to the db. They don't deal with sharding, load balancing, request routing... so they leave some performance on the table. They are still built as if it's normal to split the backend in two: app server + db. Maybe backends will learn from databases, and become sharded, redondant, and stateful. The border between app server and db could become fuzzy...