I recommend using Micronaut + Thymeleaf, its simple, easy and fast in both performance and developer productivity. Vanilla HTML, CSS and Javascript is fine. The

I recommend using Micronaut + Thymeleaf, its simple, easy and fast in both performance and developer productivity. Vanilla HTML, CSS and Javascript is fine. The best part by using Micronaut is that the documentation is really really good. I do also think a single PHP file is maybe the easiest option.