Way means, a means of doing something. Everybody has their own way of speaking.
Way also means a route from A to B, it does not have to be a route like on a journey it can also be the way means to complete a task, job = the way [route by which you will complete and navigate the journey through the task/ job from start to finish.
Very is an emphasising adjective and way before is an additional adjective describing that it is way to big to complete, by any means or by any {way journey}
And sometimes you will hear some speakers add in an extra way.
"It was way, way too big a project"
So it is just adding onto the idea of a big project too big to complete, the extra notions of by any means or by whatever method, combined possibly also with the meaning of way as a route/journey through the job, start to finish.
"It was way to big a project, we would have never finished it in a million years"= a common Expression.