This is an interesting point - my limited experience has been that with successive generations of hires, each attempts to update the practices and tools used to

This is an interesting point - my limited experience has been that with successive generations of hires, each attempts to update the practices and tools used to build the application. This leads to pockets of properly functioning Y-way code and many layers of inefficient and difficult to support bridging between X-way and Y-way. Overall, in each one of these scenarios my gut is that it would have been more efficient to attempt to optimize X-way, rather than layer Y-way on top. It always seems the goal is to incrementally migrate from X-way to Y-way, except we never seem to quite finish and frontend moves quickly enough that Z-way starts to look enticing midway through the painful migration. I think it is extremely important to differentiate between the benefits of building a fresh application Y-way initially, and the (often extremely painful) friction of migrating from X-way to Y-way. One great example of this is the recent AirBnB departure from React Native. It seems like the majority of their complaint with the framework was that it was difficult to integrate with the rest of their app - had they built from the ground up in React Native, they likely would not have experienced such integration challenges.