Vercel now supports Fastify applications, a web framework highly focused on providing the best developer experience with the least overhead and a powerful plugin architecture, with zero-configuration.

import Fastify from 'fastify'
const fastify = Fastify({ logger: true })
fastify.get('/', async (request, reply) => {  return { hello: 'world' }})
fastify.listen({ port: 3000 })

Backends on Vercel use Fluid compute with Active CPU pricing by default. This means your Fastify app will automatically scale up and down based on traffic, and you only pay for what you use.

Deploy Fastify on Vercel or visit the Fastify on Vercel documentation