Single page website, required to do it for Drupal fml.

At that point I'd seriously start to consider building the SPA with whatever the fuck I want (yii, node, ruby (ew), up to you), then write a db adapter that frankensteins the drupal db as a data store.

Have apache/nginx pointed towards the entrypoint of my router/MVC/whatnot. From there, neuter drupal so none of its front end can be accessed. But leave the admin panel accessible (I've used a subdomain before)
And there you go, SPA that's not running on drupal, but is "for" drupal.

good luck

Like don't sneak that past the client. But if they don't know what the fuck they're doing (which from the fact that they're using drupal isn't too much of a leap) and they just want it to "plug in" with what they have, this might be a possibility. It really depends on 1) their existing setup 2) scope of desired additions 3) 10,000 other things

About a year ago, I had a client I did a site for stumble upon wordpress and demand I switch over to that like 70% of the way through the project because the WYSIWYG and dashboard empowered him beyond the limits of his stupidity. After ton of bullshit I ended up keeping what I had, but making a wordpress install on the side. Then I had my ORM map itself to the wordpress tables (so ugly christ) and that basically allowed him to use the wordpress dashboard to edit content.

I was not going to turn that entire project into a fucking wordpress plugin

It's for a large University, the problem is their entire infrastructure is based on Drupal 7. So I've got to plug the site into their current system. 😥

Dude. Ain't no thang brother. I've made plenty of D7 one pagers. What are some of the requirements? Are you making it on its own install or could you use one of the other existing sites and create a page for your project. If they like D7 and you want to win some points, set it up with domain access module and allow yourself to make several one pagers for each and every department that all have one codebase. That's fewer codebases to manage in the long run when updates are needed.