What could be a software architecture of a web application without a data-tier?

Question

I'm making a web application in JSP/Servlets and Tomcat that lets you use FFmpeg online. So you just upload the file, fill the form and download it converted. There is no need of data persistence. What could be the best software architecture for the case? Thank you for your help and time :)

Answer 1

Even without data persistence layer you still should use Hexagonal architecture and SOA.

In this case your conversion logic will form the application core (by implementing domain services), a special layer that can be tested in isolation.

Then you can add more "ports" and "adapters". In your case JSP servlet/form will be the first incoming port and some special API that returns a link for a processed file will be the first outgoing port. You'll be able to easily extend your application by adding more ports: for example you can accept files using HTTP API or some message queue and write files to AWS S3 or send them via email.

Every part of the application will be completely isolated from others (which is great for testing too).