Node.js · Senior · Question 12 of 75

Why can `JSON.stringify` of a large response be a bottleneck, and what helps?

1It can't handle objects bigger than 1 MB
✓Correct answer: It's synchronous and CPU-heavy; schema-based serializers (like Fastify's) or streaming JSON reduce the cost
3It runs on the network thread and blocks sockets

Explanation

Fastify compiles a serializer from the response schema, which is faster and also drops fields not in the schema. For huge lists, paginate or stream.

Further reading

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