GraphQL: ментальная модель

GraphQL — query language, single endpoint, client picks fields, typed schema. Cures REST over-fetch/waterfall; bill = hard cache + N+1 + DoS surface.

Разбор

REST — many endpoints, fixed server shape. GraphQL — one POST /graphql, client query = response shape 1:1.

# One request replaces GET /user + GET /user/orders + GET /orders/:id/items
query {
  user(id: 7) {
    name                    # ← ask for exactly these fields
    orders(last: 3) {       # ← traverse relationships in ONE round trip
      total
      items { sku, qty }    # ← no over-fetch, no waterfall
    }
  }
}

Mental unlock: graph traversal, not endpoints. Schema = typed contract.

Итог

GraphQL = client-controlled shape in one round trip; server must add DataLoader + query guards.