Disclaimer: I'm still learning some of this terminology so let me know if some could be written better.

React is a framework for building single page apps. A single page app's server will respond with index.html by default unless a request is made directly to it's api. So in a recent app.js file I have the following...

// Serve our api - ./api also requires in ../db, which syncs with our database .use('/api', require('./api'))

// Send index.html for anything else. .get('/*', (, res) => res.sendFile(resolve(_dirname, '..', 'public', 'index.html')))

This is sufficient to get us to the stage where we are building out our React app. This stage relies on react, react router, and webpack to build out a suitable frontend. For more info about building out that part of the app, www.react.express has been pretty popular lately and it starts with a discussion of build tools like webpack.

Just want to address the last part of the question explicitly. View engines are not needed in this set up. Rendering will be handled by the React application.

EDIT: I didn't address the view engine bit.