[alexpotato]

Rewriting an application can mean different things:

1. "We are going to start over from scratch and rewrite the whole thing!"

Joel Spolksy famously said to "Never do this!"

2. "We are going to slowly refactor the whole codebase."

This can, eventually, lead you to a place where none of the original code is there so it's like a rewrite but much simpler.

3. "We are going to slowly add new places to replace the old system till there is no new system."

This is called the "Strangler App" model as described by Martin Fowler (https://martinfowler.com/bliki/StranglerFigApplication.html)

Granted, for some reason, it seems that "I retired a legacy system and rolled out a brand new one" seems to look better on a resume than "I refactored a legacy system into a better system." so your YMMV.

[steve_adams_86]

I'm not sure about the resume part. My experience refactoring legacy stuff into more modern stuff is actually a big talking point for my resume in my experience. People are always interested in why I did it, how I did it, why didn't I just build anew, etc.

Maybe that's because most jobs I apply for tend to have at least one 'legacy' system laying around that needs some help. But this is somewhat common outside of the startup scene.

Legacy in this case means an app that's maybe 7-10 years old, often written like everything happened on the back of a napkin. Sprawling, inconsistent, monolithic stuff. But not true legacy where it's written in Fortran or something in the 1500s.

At any rate, I think it's worth having refactors on your resume. I know I'd be interested in people who have done it - it's always such an educational experience.

[alexpotato]

Should have been more specific as to which industry I was referring to regarding the resume comment.

I worked for a big bank for 5 years supporting large trading systems. After the 3rd attempt to retire a legacy trading system by rolling out a new system, someone pointed out that if you are a mid level manager you don't get any resume points for refactoring old systems.

Hence, you keep trying to roll out new systems even if those systems have bugs like "switch all buy orders to sells" (true story).

[collyw]

I guess if you are replacing a system part by part as opposed to big bang rewrite, you will be more likely do make sure interfaces are well defined and components are more modular.