GraphQL vs REST: When to Use Which Architecture

For years, REST (Representational State Transfer) was the undisputed king of APIs. Then Facebook introduced GraphQL, promising to solve all our under-fetching and over-fetching problems. Is GraphQL really the silver bullet it claims to be, or does REST still have a place in modern software engineering?

The Case for GraphQL

GraphQL shines in complex client applications where the frontend UI needs to aggregate data from multiple different microservices or deeply nested relational tables. In REST, a frontend might have to make 5 different API calls to load a dashboard. In GraphQL, the client defines exactly what data it wants in a single request.

query GetDashboardInfo {
  user(id: "123") {
    name
    email
    recentOrders(limit: 5) {
      orderId
      totalAmount
      status
    }
  }
}

Verdict: Use GraphQL if you are building an API primarily consumed by a mobile app or a heavily interactive React/Next.js frontend where network payloads must be absolutely minimized.

The Case for REST

While GraphQL excels at client flexibility, it introduces severe backend complexity. HTTP caching becomes practically impossible out-of-the-box because every request is a POST request to /graphql. Furthermore, poorly structured GraphQL queries can easily lead to the dreaded N+1 database problem, effectively letting a malicious client crash your database.

REST, on the other hand, is completely stateless, natively leverages HTTP caching headers, and is universally understood by every integration tool and webhook provider on the internet.

Conclusion: It's Not a Zero-Sum Game

You don't have to choose just one. The best architecture is often a hybrid: Use REST for internal server-to-server communication, webhooks, and public developer APIs. Introduce a GraphQL gateway layer solely to serve your own frontend clients, acting as an aggregator over your REST microservices.