There Are a Few Issues
You may encounter if you’re going to have a site that makes use of application shell architecture. Firstly, it’s pretty much required that you’re going to be using some form of js framework or view library, like angular or react. If this is the case, you’re going to want to take a look at some angular.Js or react seo advice.
If You’re Using Something Else
Assuming you’re in the world of clever js front-end DW Leads technologies, to make sure you do things the pwa way, you’ll also need to be delivering the css and js required to make the page work along with the html. Not just including script tags with the <code>src attribute, but the whole file, inline.