What is the role of serverless functions in a serverless GraphQL architecture, and when might you use them?

0-2 years experience

1. 1If you need to add a new field to your GraphQL schema that fetches data from an external API, how would you implement it using a serverless function?
2. 2What happens if the serverless function backing a GraphQL resolver exceeds its timeout? How would you notice and handle it?
3. 3Describe the steps to deploy a simple resolver as an AWS Lambda and connect it to your Apollo Server.

2-5 years experience

1. 1We have a GraphQL query that aggregates data from three microservices. Walk me through how you'd orchestrate serverless functions to resolve this query, and what trade‑offs you’d consider.
2. 2During a load test, the latency of a resolver backed by a serverless function spikes. What could cause this and how would you debug it?
3. 3Explain why you might choose a serverless function over a traditional long‑running service for a mutation that triggers an email.

5-8 years experience

1. 1Design a scalable serverless GraphQL gateway that routes resolver calls to individual functions while minimizing cold‑start latency. What patterns would you use?
2. 2How would you handle authentication and authorization across many serverless resolvers without duplicating code?
3. 3If a particular resolver experiences high traffic and you start seeing throttling errors from the underlying function platform, what architectural changes would you propose?

8+ years experience

1. 1Our organization is moving from a monolithic GraphQL server to a fully serverless architecture. What are the key migration steps and how would you mitigate operational risk?
2. 2Discuss the long‑term cost and observability implications of using serverless functions for every GraphQL field versus grouping related fields into shared functions.
3. 3How would you set up a cross‑team governance model for versioning and deprecating serverless resolver functions in a large product suite?