That's great, but it sounds like this project predates the modern frameworks. It probably doesn't make sense to try to shoehorn it into a framework at this point. But to write 100,000 of framework-less JS today on a green field project seems ridiculous. 5 years ago, some person was probably bragging about their 100,000 line app built without jQuery. 5 years from now, someone will be bragging about how all they use is Backbone.
But to write 100,000 of framework-less JS today on a green field project seems ridiculous.
Why? I've worked on non-web software projects 1-2 orders of magnitude bigger that didn't need anyone's magical framework to develop and maintain a sound architecture. How come we can't just use good design that fits the project if the software we're writing happens to be the front end for a web app?
It's about picking the right tool for the job, the same as always. For some projects and some development teams, I'm sure these modern JS frameworks and tools have proved valuable and will continue to do so. On the other hand, we're currently planning another web app that is expected to grow at least as big as the one I described earlier, and no-one on the team is seriously considering using any of the current crop of front-end frameworks. That's not because we don't know what they do or how they work. It's simply because none of us thinks it's a smart idea to build such a large and hopefully long-running project with a fundamental dependency on the kind of technology that typically measures its time at the top in months.