When we fulfill orders on our phones with the shopify app, the items are listed are in seemingly random order. We have a lot of small parts that have similar photos, sku, and titles. It leads to a lot of back and forth between bins, and our efficiency and accuracy when picking orders could really be helped if they would be reordered my sku, title, or anything in the fulfillment screen.
Is there some way to have our item lists in orders sorted or is hardcoded in shopify code? I’m not even sure what the data object might be, is all of this based on the order the customer added things to the cart before submitting?
The products in an order are pretty much in the same order a user added them to their cart, so you are correct to assume that it's hardcoded that way.
Off the top of my head, one way you could solve that is by using the Order Printer app, and creating a picking list with the order number, where you could order the item's listed by any way you find easier. Granted, that would require some liquid editing of a template (in order to bring over the line items, create an array with the necessary information and reorder them so that they can match your preferred sorting), but it would work.
A quick search also reveals several picking list apps in the Shopify App store, which might fit your needs (such as Quick Pick Pick Lists—haven't tried it but seems to be able to do something similar to what you're requesting).