Instead, it becomes "final ship" code.
I tend to write ship code from the start, but do so, in a manner that allows a lot of flexibility. I've learned to write "ship everywhere," even my test harnesses tend to be fairly robust, ship-Quality apps.
A big part of that, is very high-Quality modules. There's always stuff that we know won't change, or, if so, a change is a fairly big deal, so we sequester those parts into standalone modules, and import them as dependencies.
Here's an example of one that I just finished revamping[0]. I use it in this app[1], in the settings popover. I also have this[2] as a baseline dependency that I import into almost everything.
It can make it really fast, to develop a new application, and can keep the Quality pretty high, even when that's not a principal objective.
[0] https://github.com/RiftValleySoftware/RVS_Checkbox
[1] https://github.com/RiftValleySoftware/ambiamara
[2] https://github.com/RiftValleySoftware/RVS_Generic_Swift_Tool...