The Evolution of Airbnb’s Frontend
! @spikebrehm

Spike Brehm ____________________________ @spikebrehm !
@AirbnbNerds since 2011

1. A Brief History of
airbnb.com 2. Modernizing our JavaScript Stack 3. Airbnb&Isomorphic JavaScript

A Brief History of airbnb.com

! airbedandbreakfast.com2008

! airbnb.com2009

! airbnb.com2012

! airbnb.com2015

Rails 2.x MySQL Vanilla CSS
Prototype.js !2009

Rails 3.x, Java MySQL, Redis,
HDFS, Postgres, DynamoDB SASS, O2 jQuery, Backbone, Handlebars !2012

! Bootstrap-inspired CSS frameworkO2

Rails 3.x, Java, Node.js MySQL,
Redis, HDFS, Postgres, DynamoDB, Kafka, RabbitMQ, … SASS, O2 jQuery, Backbone, Handlebars, React, CommonJS, ES6 !2015

Modernizing our
JavaScript Stack

A. JavaScript Libraries

Flight

! Listing management tools

Hitting a Wall with Backbone&Handlebars
Backbone & Handlebars approach falls apart as UI components become more dynamic. No data binding, so have to either: 1. Re-render whole view when model changes (slow, lose DOM state like focused fields). 2. Drop down to manual DOM manipulation.

Airbnb <3 React React makes
it easier to build&maintain stateful UI components. React makes it easier to reason about data flow in your app.

B. Asset building

Sprockets Rails asset pipeline: manages
JavaScripts, stylesheets, images, etc. Written by Ruby devs to solve problems of simple web apps.

JavaScript </3 Sprockets Doesn’t solve
JavaScript dependency management: 1. Local dependencies (application code) 2. External dependencies (third-part libraries)

/* application.js */ //= require_tree
. /* application.js */ ! //= require ./models/listing.js //= require ./collections/listings.js //= require_tree . What if one file depends on another? Bad: Order matters Bad: Objects attached to `window` Bad: Implicit dependencies Local dependencies

$ cp ~/Downloads/backbone.js app/assets/javascripts/vendor/ backbone-1.1.12.js
/* application.js */ ! //= require vendor/backbone-1.1.12.js ... //= require_tree . What if I want to use Backbone? Bad: Manually download Bad: Manually versioning Bad: Implicit dependencies External dependencies

CommonJS&NPM to the rescue

/* collections/listings.js */ var Listing
= require(‘../models/listing’); ! module.exports = ... Good: Explicit dependencies Good: Don’t worry about ordering Good: Objects not leaked to `window` Local dependencies

/* collections/listings.js */ var Listing
= require(‘../models/listing’); var Backbone = require(‘backbone’); ! module.exports = Backbone.Collection.extend({ ... }); Good: Central management Good: Explicit dependencies External dependencies $ npm install --save backbone@1.1.2

Explicit Dependencies

Browserify* Use CommonJS syntax in
client-side modules: `require` and `module.exports`. Package dependencies from NPM. Transforms. * or Webpack

Browserify Transforms Handlebars var template
= require(‘./templates/user.hbs’); ! var html = template({name: “Spike”}); es2015 import Header from ‘./Header.jsx’; ! const numMonths = 36; ! let photos = users.map((user) => user.photo);

Airbnb&Isomorphic
JavaScript

JavaScript code that can be
shared between environments.

+

Client-side MVC Client Server Your
app API

+

Client + server MVC Server
Client Your app API

Performance Initial pageload speed. SEO*
Crawlable single-page apps. Flexibility Run code anywhere. Maintainability Reduce code duplication.

Performance

Client-rendered app Download skeleton HTML
User sees content Download JavaScript Fetch data from API Evaluate JavaScript Exacerbated on mobile: high latency, low bandwidth

Server-rendered app Download full HTML
Download JavaScript User sees content Evaluate JavaScript

Rendr

Moving Away from Rendr at
Airbnb

It was revolutionary to share
code between client and server using Node.js…

10% 90% Rails Node.js …but
too hard to share code between server and server— between Rails and Node.js. Long tail of features to rewrite in JavaScript: 1. CSRF tokens 2. Custom headers, i.e. CDN 3. Middleware 4. Application code

Do we rewrite everything in
Node.js?

The single worst strategic mistake
that any software company can make: ! Rewrite the code from scratch. Joel Spolsky

A New Approach to Isomorphic
JavaScript at Airbnb

Browser. Rails. App.jsx Fetch JSON
data Node.js.App.jsx

Mystique: Node.js rendering service for
React components Allows us to render React components on the server from within Rails. Built on Iso, tiny utility for isomorphic bootstrapping of React components. https://github.com/goatslacker/iso

! https://www.airbnb.com/getaways/san-francisco A/B testing now

Thanks!!
!
@spikebrehm
@AirbnbNerds