If I was the author of Gatsby or NextJS, one change that I would make is to let users define routing with a configuration file rather than through a file based approach.

If you don't know already, in both NextJS and Gatsby, you create new pages by adding files to the pages folder in your source code. So if you wanted to have an about page you can just create pages/about.js and Gatsby or Next will figure the rest out.

I get why it's done this way, it allows routing with zero configuration. But while you get the benefit of not having to configure routing, the downside is that you have to do it this way, and there's no alternative. So if you end up with a complex routing structure to your site, the only way to organize those routes would be with nested files in the pages folder. This strategy works great when you have a /, /blog and /about routes, it gets tricky when you have multiple nested routes like: /products/:category/:subcategory/:product/pricing. With a route like this btw, your folder structure in nextJS will look something like this:

src/
	pages/
		[category]/
			[subcategory]/
				[product]/
					pricing.js

The alternative here is rather simple, allow routing based on a configuration file. For NextJS you could have a file called navigation.tsx that sits at the root of your project and roughly looks like this:

const pages = [
	{
		route: '/'
		component: Home,
		getStaticProps: homeGetStaticPropsHandler
	},
	{
		route: '/blog',
		component: Blog,
		getStaticProps: blogGetStaticPropsHandler
	},
	{
	 route: '/post/:post',
	 component: BlogTemplate,
	 getStaticProps: blogTemplateGetStaticProps,
	 getStaticPaths: blogTempalteGetStaticPaths,
	}
]

export default Pages

Look how much nicer this is than having a pages folder that would inevitably look like this:

/pages
	/home.js
	/blog.js
	/post
		/[slug].js

Vercel and Gatsby, please take a page out of React Router's book and let us add a configuration file that defines routing rather than making us go through file based routing.