React Finland

Performance can be a concern when working with bigger applications. Sometimes issues can come up when a low latency in the UI is required. It’s for this reason why I wanted to have a performance session in React Finland 2019.

Anna Doubková  —  Practical Performance for React (Native)#

When working with React Native, there are specific parts of the stack where you can run into performance issues. In her talk, Anna discusses how her company approached optimizing their application.

When it comes to React and React Native, the basic rules of optimization apply. Measure before changing anything. For this purpose, React provides great tooling these days and you should use it to pinpoint the bottlenecks in rendering.

• pdf slides
• React Developer Tools

Sven Sauleau  —  WebAssembly — The Next Big Platform#

There’s only so much you can do with vanilla JavaScript. One of the recent developments in browsers is the introduction of WebAssembly. It’s a new compile target that gives a promise of high performance.

For CPU bound tasks, it’s possible to push calculation to WebAssembly side of the fence while interacting with the code through JavaScript. It’s exactly this that Sven demonstrated in his talk.

• pdf slides

Conclusion#

Even with the improvements in React, performance can remain an issue. It’s important to at least learn how to measure before doing blind changes. Often in software architecture, there can be trade-offs to be made so that the desired level of performance can be reached.