A product, with the business model in the architecture.
Subscriptions, tenancy, roles and reporting are not features added later. They are the shape of the thing, and they are decided in the first week.
A software product is not a bigger web application. It is an application plus a business model, and the model reaches into every layer: who can see what, what a plan allows, when access ends, what happens to the data when someone leaves.
We design that first. One codebase serves every account, each account's data is isolated by the data model rather than by hope, and the reporting that justifies the price is built alongside the product rather than bolted on when the first renewal comes around.
This is also where a studio earns its keep on restraint. Most first versions should ship with fewer plans, fewer roles and fewer settings than anyone wants. We will argue for that.
Tenancy
How accounts are isolated, and what it costs to move a customer between plans or regions.
Billing
Plans, trials, proration and dunning — the unglamorous half of a subscription product.
Roles
Owners, members and guests, with permissions the customer can reason about without support.
Reporting
The numbers a customer renews on, and the numbers you run the business on. They are not the same.
If the model is not settled yet, that is the first engagement — not a reason to postpone the build.