I worked on multiple Django monolith projects in the past years where parts of it with heavy client-side logic were offloaded to tiny Vue.js applications injected into the html template.

If data requires reloads or manipulations a side restful api needs to be created along the main endpoint which renders html. But it's fairly straightforward with DRF and the enforced by default apps/models structure of Django.

Until a certain point I find this arrangement enjoyable to work with. Once it stops, it's clear as day that the page should be rewritten from scratch with rendering on client side.