A stack needs an operating plan
Choosing the database is one part of hosting an application. The web process, background work, file storage, releases, access controls, and recovery procedures need to work together.
Start with the PostgreSQL web-app guide. It describes a small application with private uploads and background jobs, compares managed hosting with virtual-machine operations, and provides a worksheet for a complete cost estimate. Its example inputs are planning assumptions rather than capacity or price claims.
Read the guide, then check the products
Use the guide to define what the application needs. Follow the linked service categories to compare the documented offerings, then verify the selected region and configuration before provisioning.
If you need a partner to implement and maintain that plan, review Hapy’s cloud infrastructure capability. The guide explains the decision; the capability page explains how an engagement can be scoped.