Frontend:
Create a web page that contains a comment feed with the ability to insert new comments and filter the existing comments. Use the attached design as a guideline for your web page. To create the page, use one of the currently popular web application frameworks (such as AngularJS, Backbone.js, React, etc.) The web page should include a form with 2 fields - email and message text fields - and a submit button. The submit button should add a new item to the feed below the form. The item that will appear in the feed should contain a gravatar photo (https://en.gravatar.com/) that matches the inserted email, the email and the message. The web page should also include a filter area which allows the user to filter the items. Use flexbox to construct the page layout
Backend:
Implement a backend service that stores/retrieves the comments. The service should be implemented in either Node.JS, Java or Scala. Use either MongoDB or Redis as persistence layer.