GraphQL Online Test to screen candidates with GraphQL skills effectively

GraphQL offers an efficient, robust, and flexible approach to developing web APIs, making evolving and enabling powerful developer tools easier. The GraphQL Online Test assists recruiters in evaluating candidates' GraphQL skills. Subject matter experts have designed this test to assess and hire GraphQL developers per industry standards.

What is GraphQL?

GraphQL refers to a query language for APIs and runtime to fulfil those queries with the existing data. GraphQL offers a complete and understandable description of the data in the API.

What is inside this GraphQL Test?

The GraphQL Test consists of thirty multiple-choice questions to be completed within forty-five minutes. These questions are of intermediate difficulty level. The experience range needed is three to five years.

What skills does this GraphQL Online Test cover?

The GraphQL Test covers the following skills: 

GraphQL – Validation, GraphQL - Query Operation, GraphQL – schemas, GraphQL - Type system, GraphQL – Architecture, GraphQL – Mutations, GraphQL – Operation, GraphQL – Variables, GraphQL – Inheritance, GraphQL - Using variables inside fragments, GraphQL - Asynchronous resolvers, GraphQL – Introspection, GraphQL – Fragments, GraphQL - Dependency Injection and GraphQL – Execution.

What roles can you assess using this GraphQL Test?

• GraphQL developer  
• GraphQL API developer  
• Webservices developer  
• API architects  
• Software engineers  
• Front-end developers  
• Back-end developers

Sample questions and answers

1. What is introspection in GraphQL?  

Introspection in GraphQL is the ability of a GraphQL server to give information about its schema and types at runtime. It lets clients query the server's schema and discover the available fields, types, arguments, and directives. This characteristic is built into GraphQL and is used by multiple tools and libraries.  

2. How does GraphQL make use of the data-loading process?  

When the users give the data in GraphQL, it retrieves a minimum amount of data the client needs. Even if the object model consists of many fields, the client can ask for only the required fields.  

3. How does GraphQL help developers choose protocols other than HTTP to implement on the server?  

The GraphQL API is operated over HTTP. It is a transport layer agnostic technology. Here, one can choose protocols other than HTTP to implement on the server.  

4. What is under-fetching?  

Under-fetching is a response where clients do not get enough data. The under-fetching responses do not have enough data with a call to an endpoint, so one must call a second endpoint to fulfil the request or various API calls to fetch the complete data.  

5. What is the usage of object types in GraphQL?  

The resources that clients can access are called objects. Objects consist of a list of GraphQL fields.  

6. What is the purpose of an interface in GraphQL?  

In GraphQL, an interface lists the standard fields of a GraphQL object. Other objects can utilize this interface to inherit properties.  

7. What is the union in GraphQL?  

In GraphQL, sometimes we must represent multiple objects, which is why union is used. Using a union, the user can define more than one type as a return type.  

8. What is a resolver in GraphQL?  

A resolver handles queries and gives a response to the GraphQL query.  

9. What is a GraphQL subscription?  

GraphQL subscriptions provide a mechanism for real-time data updates, leveraging the WebSocket protocol. They elevate user experiences by delivering immediate responses to data changes.  

10. Explain fragment in GraphQL.  

GraphQL uses the fragment when the query is vast and contains reusable units. One can create a fragment by taking the reusable part and using that fragment in the query. The fragment concept arranges the code and avoids duplicate code.