Most of the time the default Next.js server will be enough but there are times you'll want to run your own server to integrate into an existing application. Next.js provides a custom server api.
Because the Next.js server is a Node.js module you can combine it with any other part of the Node.js ecosystem. In this case we are using express.
Preview the example live on StackBlitz:
Execute create-next-app with npm or Yarn to bootstrap the example:
npx create-next-app --example custom-server-express custom-server-express-app
# or
yarn create next-app --example custom-server-express custom-server-express-app