[barking]

I'd like to see some idea of what they mean by big. An order of magnitude in terms of lines of code and the number of engineers they had for the job and how long it all took versus how long the original took to write etc. One of the things that scares me about something like this are all the seemingly illogical bits of code that were added over time and are actually that way for a reason because they fix some edge case or whatever. Hard to see those not getting swept away in a rewrite as well as a whole bunch of new rarely occurring issues added. A complete rewrite strikes me as something that's almost guaranteed to be buggier than what it replaces, at least for awhile.

[mgkimsal]

> A complete rewrite strikes me as something that's almost guaranteed to be buggy

Likely buggy, but buggy in different ways. The real test will be in measuring the number and quality and severity of bugs, as well as the ability to identify and repair them in both systems. A testable system with good test code written may still be 'buggy', but will help foster a sense of confidence when making the fixes required.

[LandR]

>I'd like to see some idea of what they mean by big. An order of magnitude in terms of lines of code and the number of engineers they had for the job and how long it all took versus how long the original took to write etc.

Yeah, at my last place before I left, they were looking to do a rewrite of their main project that had been the result of years of hundreds of developers working on it. The time-scale was wooly, but was expected to be between 5 and 10 years and probably require ~200 developers and testers.

This was rewriting millions of lines of code, very little would be reusable.

I don't know if they went ahead with it or not, but it was looking like it would descend into chaos.

[eej71]

What prompted everyone to want to rewrite so much code?

[LandR]

They were on a system where if bugs existed past a certain date of them being logged, their was financial penalties that had to be paid.

Also adding new features was incredibly slow, painful and dangerous. Even a minor change resulted in so much manual regression needing to be done. It was absurd.