How do multi tenant applications load different front end themes?

I want to create a simple replica of a multi-tenancy application such as shopify in Laravel 5. When a new tenant comes to my platform, I need to design that website (create views, stylesheets, etc) and store it somewhere.

I am using a same schema same database approach and understand how to filter through data for each client but do not understand the idea of how to store/load custom images and css per tenant dynamically.

For example, Shopify/Wordpress clients are able to choose different themes or upload their own. I am confused on how this is done on the backend.

Q: How do I store tenants' resources (assets, views, css, etc.)?

via Chebli Mohamed