A lesson can be derived form the Facebook , PHP and HipHop story. They did not rewrite the PHP code in another
language, they just made it go faster with HipHop by compiling PHP into C++, and the compiling that into binary.
The end users neither cared nor knew about this change. I do not think the development or release timelines of new features were impacted at all.
What this example serves to illustrates is that one should consider all possibilities before making a decisions regarding code that has been in production and has active users. Rewriting production code should not be the only option you should have on the table.
Sure, HipHop gives a fixed percentage increase. It feels a little strange to compare this to a software re-architecture though, since fixing something Fundamentally Wrong can have compoundingly good effects down the road.
The end users neither cared nor knew about this change. I do not think the development or release timelines of new features were impacted at all.
What this example serves to illustrates is that one should consider all possibilities before making a decisions regarding code that has been in production and has active users. Rewriting production code should not be the only option you should have on the table.