Browser Rendering Optimization - Google

The News Aggregator App - Turn an unusable app into a high performance, 60 frame per second experience. You'll be given a news aggregator app that uses the Hacker News API to display the day's top stories. The news aggregator has lots of performance issues. You'll demonstrate your understanding of performance by destroying all the jank and creating an experience that users will love.

• You'll play Jank Invaders to develop your eye for jank!
• You'll learn how the browser turns HTML into pixels on the page
• You'll learn how different CSS styles affect the rendering pipeline differently.

• You'll learn how there are four distinct phases in an app's lifecycle: Response, Animation, Idle and Load (RAIL).
• You'll learn how your frame budget changes depending on where the user is in RAIL.
• You'll practice thinking through app workloads at different stages in RAIL.

• You'll learn how to make sense of the Timeline panel in Chrome DevTools.
• You'll practice profiling a few different apps to find the source of jank.

• You'll optimize JavaScript to hit 60fps during animations.
• You'll move expensive JavaScript operations off the main thread and into Web Workers.
• You'll debug a janky copy of a production quality app - the QR Snapper.

• You'll learn how accessing the wrong CSS properties at inopportune moments can create loads of extra work for the browser.
• You'll debug multiple instances of one of the nastiest performance problems - Forced Synchronous Layout.

• You'll practice profiling layer and paint performance with the paint profiler tool in the DevTools Timeline.
• You'll manage and optimize layers to reduce the number of steps the browser needs to take to render each frame.
• You'll demonstrate everything you've learned about performance as you de-jankify the News Aggregator App!