One Job, No Data Kept

The app does one thing: it lets a sales rep place an order in a customer's name. It needs customer and pricing data to do that, and it reads that data from Shopify at the moment it is needed.

Nothing is mirrored into storage of ours. There is no second copy of your customer list sitting somewhere, which means there is no second system to secure and nothing left behind outside your own systems when the app is uninstalled.

Saal: Sales Agent was built to be as stateless as possible from the start. Put simply, the data needed to carry out a given function (signing in on behalf of a customer, placing an order, and so on) is not stored in my database — it is passed along with every call.

Some information does of course still have to be stored, such as which shops have installed the app, or which plan is currently active.

Keeping the number of states low has one more decisive advantage: it makes automated testing far easier. Instead of elaborate fake data, many tests can even be generated semi-automatically from the possible paths through a function.