Frontend frameworks can be used in conjunction with backend frameworks by allowing the frontend to communicate with the backend via APIs, enabling the separation of concerns and supporting the development of full-stack applications.

Front-end frameworks can be used with back-end frameworks, as they are used for different purposes. Front-end frameworks are used for the user interface and user experience of a website, while back-end frameworks are used for the server-side logic, database integration and API connectivity ¹. Here are some examples of front-end and back-end frameworks being used together 

- React (front-end) with Django (back-end) for building complex, data-driven web applications

- Angular (front-end) with Node.js (back-end) for building fast and scalable web applications

- Vue.js (front-end) with Ruby on Rails (back-end) for building robust and maintainable web applications

- Ember.js (front-end) with Laravel (back-end) for building complex web applications with a strong focus on convention over configuration

- Backbone.js (front-end) with Express.js (back-end) for building fast and flexible web applications with a strong focus on RESTful APIs.