[ryantownsend]

I agree with the above. That said, even if you are doing something new, you don't need to reinvent the wheel – it may be worthwhile taking a look at https://www.contentful.com/ (not affiliated, just an interesting service) and utilising their API to build an application which purely delivers the added value.

[pavlov]

Prismic.io is another excellent "CMS as a service":

https://prismic.io

I've used it on a project and was quite pleased. Using their API, separating content publishing from the presentation becomes much more robust than with a traditional integrated CMS that you customize using themes or whatever.