Thanks @JonWright for your reply. I've gone through it but I have a problem connecting to Postgres and using Polaris with crud operations on Postgres. If you know how to do it I would appreciate sharing your thoughts !
Here is a tutorial help you build a restful service with nodejs and PostgreSQL.
And you can use this lib for connection pg
Polaris is only a front-end framework. If you want to support a CRUD service, you need to learn a little more other technologies.
Thanks @Sempr for sharing. Do you mean Polaris elements like "text field" can't be used as normal HTML elements for form submission or displaying data from other data sources like Postgres database? I am still new to all this but logically I think it should support. I would appreciate more clarification.