Hugo performance optimizations
To have a silky smooth start you’ll need any code that affects layout to be included in the first render. Ideally you should fit all HTML and CSS needed by first render within 14KB (search for TCP slow start to dig deeper). Size of images needs to be predetermined so that rendering them won’t affect layout. There shouldn’t be any JS that affect layout either.
User first/Content first The reason users come to your site is to consume your content (read your posts, buy your product or whatever).