Kalai

Both Angular 2.0 and ReactJS aim for high performance, but their approaches differ. React's virtual DOM and efficient reconciliation algorithm make it fast. Angular 2.0 introduces several performance improvements, but whether it matches React's speed depends on various factors like your application's complexity and optimization efforts.

There are several alternatives to AngularJS 2.0, ReactJS, and PolymerJS, depending on your specific needs and preferences. Some popular options include: 1. Vue.js: Known for its simplicity and flexibility, Vue.js is a progressive JavaScript framework for building user interfaces. 2. Svelte: It's a relatively new framework that shifts the work of building applications from the browser to the build step, resulting in highly optimized code. 3. Ember.js: This framework offers a strong convention-over-configuration philosophy and is well-suited for large-scale applications. 4. Backbone.js: While not as feature-rich as some other frameworks, Backbone.js is lightweight and provides structure to web applications. 5. Aurelia: A modern, forward-thinking framework for building browser, mobile, and desktop applications. Each of these frameworks has its own set of strengths and weaknesses, so it's essential to evaluate them based on your project requirements and team expertise.

Instagram uses Django and ReactJS together to build their web and mobile applications. Django is used for the backend of the application, handling tasks such as user authentication, data storage, and API development, while ReactJS is used for the frontend, building the user interface and handling client-side logic.