Most of the times the default Next server will be enough but sometimes you want to run your own server to customize routes or other kind of the app behavior. Next provides a [Custom server and routing](https://github.com/zeit/next.js#custom-server-and-routing) so you can customize as much as you want.
Most of the times the default Next server will be enough but sometimes you want to run your own server to customize routes or other kind of the app behavior. Next provides a [Custom server and routing](https://nextjs.org/docs/advanced-features/custom-server) so you can customize as much as you want.
Because the Next.js server is just a node.js module you can combine it with any other part of the node.js ecosystem. in this case we are using [Koa](http://koajs.com/) to build a custom router on top of Next.
