A dummy bank simulator on Cloudflare D1: open an account at any branch, credit and debit it over the API, and watch a dummy company auto-charge it every hour. No real money, no real accounts.
All 7 branches, their IFSC codes, managers and employees.
Create a dummy account, credit/debit it, and subscribe it to an auto-charging company.
How the bank works under the hood, and every endpoint it exposes.