The answer here is a custom theme. 
Building you own theme allows you to create new snippets (building blocks) and modify the basic website pages (product page, shop page, etc) as you would other backend views, using template inheritance. It can get quite messy fast, the dev experience working with snippets is not that great and quite opaque, but anything can be achieved. It even allows you to insert OWL components, meaning you can build pretty much anything that a modern web framework can.