GraphQL.

Query language for APIs with strong typing. Covers 8 sub-skills.

• GraphQL · 1 of 3

  Subscriptions & Real-time

  A GraphQL field messageAdded(channelId: ID!): Message! pushes an event to connected clients each time a new message is created. Under which root operation type must this field be defined?

  ASubscriptionBNotificationCObservationDEventStream

• GraphQL · 2 of 3

  Schema & Type System

  A GraphQL union can directly include which kind of members?

  AObject types onlyBInput types onlyCEnum types onlyDScalar types only

• GraphQL · 3 of 3

  Resolvers & Data Sources

  What is the primary mitigation for N+1 query explosions in resolver trees?

  ABatch and cache lookups per request via data loadersBDisable nested object fields on the public schemaCPush the data-fetching layer down into the clientDGrow the database connection pool to absorb the fan-out