Paris - London - New York
@jiherr
(because it is)
Pick a key user journey
Use an Android test device
Plug it in your computer
Start the app
Run through the journey
adb shell dumpsys gfxinfo com.example
Janky Frames
time
Performance of key user journey
20%
https://medium.com/@addyosmani/the-cost-of-javascript-in-2018-7d8950fbb5d4
Premature optimization is a waste of time
Do not guess which part of the code should be fixed
If you have an intuition, measure it!
If you don't have a clue, read the ... amazing manual ❤️
https://facebook.github.io/react-native/docs/performance
With the React Native profiler
React Native profiler
why-did-you-update
Firebase Performance Monitoring
...
time
Performance of key user journey
38%
19%
15%
Janky Frames
When you stop caring...
Paris - London - New York