Common Mistakes in Node.js + GraphQL Projects

A Developer’s Personal Reflections on Pitfalls and How to Avoid Them

When I first started using GraphQL with Node.js, I was thrilled by the flexibility and power it gave me. The ability to define exactly the data I wanted and get it in a single response felt like magic compared to the rigid nature of REST APIs. But as with all powerful tools, GraphQL comes with its own set of challenges. Over the past few years, I’ve encountered a number of recurring pitfalls — some in my own code, others while helping teammates or auditing client projects. This post is a candid summary of those common mistakes and how to avoid them.

1. Over-fetching and Under-fetching: Still a Problem?

One of the primary reasons people switch to GraphQL is to avoid over-fetching and under-fetching. Ironically, I’ve seen developers recreate the same problems they were trying to escape.

Early on, I built a GraphQL API where the User type returned not just the user’s profile but also their recent orders, comments, and preferences — by default. The idea was to make things easier for the front end. But this bloated every request with unnecessary data, even when the client only needed the user’s name and email.

Lesson learned: Resist the temptation to include too much in your resolvers.

Fix it tip: Design resolvers to be lean and lazy. Use tools like dataloader to batch and cache where needed.

2. Poor Schema Design: The Silent Saboteur

A poorly designed schema can haunt your project. I once inherited a GraphQL project where the types were named inconsistently — some were singular (User), some plural (Posts), and some overly generic (Item, Thing).

Lesson learned: Schema is your API contract. Treat it like your codebase architecture.

Fix it tip: Follow naming conventions. Use Input suffixes for input types. Don’t be afraid to refactor.

3. Ignoring Resolver Performance

Resolvers seem simple on the surface. But just because each field has its own function doesn't mean you can get away with inefficient code. I once profiled a GraphQL API where every query took over a second to respond. The culprit? N+1 queries in almost every nested resolver.

Lesson learned: GraphQL's nested nature means you need to be extra mindful of database access patterns.

Fix it tip: Use dataloader to batch DB calls. Consider writing custom resolvers that fetch related data in bulk.

4. Too Much Logic in Resolvers

It's tempting to treat resolvers like mini controllers, packing them with business logic. But doing this makes your code hard to test and maintain.

Lesson learned: Keep resolvers thin. Move business logic into service layers.

Fix it tip: Treat resolvers as glue between schema and business logic. Delegate work to reusable services.

5. Lack of Error Handling and Validation

GraphQL gives you flexibility in how you handle errors. But that doesn’t mean you should ignore them.

Lesson learned: If something goes wrong, make sure the client knows.

Fix it tip: Validate inputs manually or with libraries like Joi or Zod. Use structured error classes.

6. Unsecured Endpoints and Lack of Authorization

This one hurts to admit — I once deployed a GraphQL endpoint with no auth checks on mutations. It was behind a login wall in the frontend, so I naively assumed it was safe.

Lesson learned: The client is never the gatekeeper. Always validate permissions at the resolver level.

Fix it tip: Use context-based access control. Inject user roles into the context and check them inside resolvers.

7. Not Using Fragments and Reusable Queries

On the client side, I’ve seen frontends duplicate the same query structure in dozens of components. This leads to inconsistencies and maintenance nightmares.

Lesson learned: GraphQL fragments exist for a reason — use them to keep queries DRY.

Fix it tip: Create shared fragment files. Tools like Apollo Client and Relay encourage this pattern.

8. Skipping Documentation

Because GraphQL is self-documenting, many developers think they don’t need to write any additional docs. But trust me, SDL comments aren’t enough.

Lesson learned: Self-documenting doesn’t mean self-explanatory.

Fix it tip: Document each mutation’s purpose, usage, and side effects. Use tools like GraphQL Voyager.

9. Skipping Testing

GraphQL makes it easy to test at the query level, yet many people skip it because mocking can seem intimidating.

Lesson learned: GraphQL queries and mutations deserve the same testing rigor as REST endpoints.

Fix it tip: Use tools like apollo-server-testing or graphql-request. Write integration tests for queries and access control.

10. Overcomplicating Your Setup Too Early

I once helped a team that used Apollo Federation, Prisma, Redis, Kafka — all in their first MVP. The result? Slow development and difficult debugging.

Lesson learned: Keep your stack simple until your use case demands complexity.

Fix it tip: Start with a single server and clean resolver structure. Add more tools only when truly needed.

Wrapping Up

GraphQL and Node.js are an incredibly powerful combo, but like any stack, they require discipline and best practices. These mistakes aren’t signs of failure — they’re milestones in a developer’s journey. I’ve made nearly every mistake on this list, and each one taught me something new.

If you’re just getting started, focus on simplicity, readability, and performance. And don’t be afraid to refactor — good APIs evolve.

What mistakes have you seen in GraphQL projects? I’d love to hear your war stories too.