After this step: you understand the selected solution, its limits, and how it will be accepted.
First describe the scenario: start → action → result, including no data and an error. Then learn the elements this project needs: interface, logic, data storage, possible accounts, and hosting. Architecture is the division of responsibility and the connections between those elements.
Ask for one proposed technology set and one sensible alternative. You should understand why you choose it: how it runs, what it may cost, what must be maintained, and how you can move data if you change your mind.
Read the agreed product description and plan. Map the first scenario: what the user does, what they see, and where data is stored. Include no data and an error. Propose the simplest technology set and one sensible alternative. For both, explain benefits, limits, running, maintenance, costs, and ability to move data. Check current prices and features in official sources. Do not assume that we need accounts, a server, or cloud. Show decisions to make. After my choice, save them in the existing plan. Identify the screens needed in the first scenario—we will design them in the next step. Do not begin building the application yet. Do not buy services or publish the application.
Google Cloud is in my workshop. I tested Vercel and Supabase, but they did not become part of my set. In your project the choice follows the need; comparing those services can be an exercise, not a ready recommendation. Current prices and properties require current official sources. The simplest project may need none of these sets.
Record: the agent adds requirements to the product description. In the plan it records selected technology, how it works, needed screens, and the reason for the decision. Add a separate architecture description when the project is complex enough that the plan no longer suffices.
Check: you know the reason for the choice, cost unknowns, and the first-scenario test. You know which screens need design. Buying a service and publishing require your separate decision.