Introduce a set of robust unit tests. The tests should check intended behavior of system. The tests are thus like a specification, that need to be satisfied no matter what new grand feature we introduce or which feature we de-support.

The feature to reset the password needs to be implemented. It seems at this point that we can send a link by mail to reset the password. This needs considerations from encryption perspective.

To facilitate search on existing reviews.

When a signup fails due to the presence of same Email Id in database, we need to provide a way to re-enter a different Email Id. Right now, we are just showing a simple page saying: "Ooops, this mail id exists! Go back and try again."

On home screen, when user searches for a book, it should show list of reviews existing on ISBN of listed 5 books. So, when review is posted, store ISBN number too.

The API endpoints in server.js need proper comments to describe their function and their return values. It should clearly specify the error scenarios. Also, this makes it easier to jump in and contribute.

User should be able to edit content when logged in. Decide which reviews should be editable, one's written by same person, or all reviews.

Need to implement the POST handler for the /add URL path.

It fails to work for the following two cases:
1.) When there are more than one author for the book.
2.) When there is no author for the book(as returned by Google Books API).

Keep this button on every page.

There should be two views for the home screen, one for a logged in user, and another for a way-farer(not logged in). Make sure that log-in works, even when JS is disabled.