Good question - and one that tells me something. You're familiar with modern front-end development and that's something we can dig into. Why would you want to avoid full page refresh? When would I use a SPA versus more traditional SSR? What about serving something mostly static with progressive enhancement? What frameworks might you consider for developing such a SPA? Which have you worked with in the past? What did you like about them? Any you're looking to work with in the future? How do these frameworks work - i.e. are you someone that hacks on them and is concerned with shadow DOM and optimizing diffs and re-rendering and data binding...
That's why I really like this question - it's just such a cool jumping off point.