The old WMS app was functional at best. After looking through the code I realized that no architecture was chosen, there was no structuring in the files and on top of that the entire program was made using linear layouts. Kotlin and Java code is used randomly throughout the project as well and the average line count on an activity sits around 350 lines. I checked and it seems that the logic is included in that as well. All of the logic seems to be written within the activities themselves and all of the code is contained within one module.

All of this doesn't mean the app won't work but it does mean it is significantly harder for a different developer to learn the code and make changes to it.

So, with my eye on efficiency I decided not to use any parts of the old WMS app other than looking at its flaws and trying to fix them in my new product.