For a while I was employed at a shop that was a sort of unified platform and on that platform we would support a number of tools - these tools were usually developed by contractors that would get a complex set of business rules and build a solution to fit - then we FTEs would take care of the plumbing and platform tech debt... Unlike how a lot of places like that might look with outsourcing our contractor pool was pretty steady so while they didn't technically continuously work for the company they were essentially co-workers.

It was an interesting place to be but suffered greatly from a lack of permanence in the roster - for a few years tings were great - then some of our regulars moved on and were replaced with more flaky people. I assume it was just the specific mix of folks that made that setup sustainable while it was.