I year ago, I made a Point of Sale (POS) terminal application for a client with Angular and Spring Boot.
The frontend consists of two main part. In the checkout page, where one can choose from all the available products, save new orders to a table or calculate receipts. On the second page, administrators can add new or edit existing products to the system.
Main goal of the design was to help practical UX for a touchscreen.
The role of the backend is only to save/read products into the database and to run a cron job every day and sends daily, weekly and monthly statistics via email. This could have been an ideal serverless application on AWS Lambda but they required to run it on a local machine so they run the jar file on a Raspberry PI.