Optimize App Startup by Background Loading of Firebase Remote Config

[nilsreichardt]

Description

In this pull request, we made significant changes to the way our application fetches and activates the Firebase Remote Config data to improve app start-up times.

Previously, our app fetched Firebase Remote Config data during its start-up sequence. This fetch-and-activate approach was a major contributor to the 11 seconds startup time our app was experiencing.

We have now moved the Firebase Remote Config fetch process to execute in the background after the application has started. This ensures that the app is not blocked waiting for these config values during startup. The fetched config values are activated on the next app launch.

This change has led to a considerable improvement in app startup times. Initial tests show startup times have dropped to just 2 seconds, down from 11 seconds - a more than 5x improvement.

Disadvantages in this strategy

The disadvantage in this strategy is that the values activated on the next launch. When there is a critical change, the user doesn't receive the values immediately. However, since we started Sharezone, 5 years ago, we never had this case. Therefore, I think it's overkill to trade bad app start times against the possibility to update critical values maybe someday.

Benchmarks

Name	Time
Before the changes	11 seconds
After the changes	2 seconds

The app start is now 5,5x faster than before when using an EDGE connection.

Demo

(In the benchmarks table, I removed the time I needed to open the emulator and click the "stop" button)

Before

Screen.Recording.2023-07-21.at.12.20.44.mov

After

Screen.Recording.2023-07-21.at.12.24.15.mov

Using the values for the next start

Screen.Recording.2023-07-21.at.12.54.26.mov

Related Tickets

Fixes #696

[docs-page]

To view this pull requests documentation preview, visit the following URL:

docs.page/sharezoneapp/sharezone-app~697

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[github-actions]

Visit the preview URL for this PR (updated for commit 787a3e0):

https://sharezone-test--pr697-fetch-remote-config-tqkxc9kh.web.app

_{(expires Wed, 02 Aug 2023 11:14:42 GMT)}

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_{Sign: 4cb3ae61e1e018abfd9841fd3239f5b49ccc034b}

[Jonas-Sander]

LGTM, see comments

[Jonas-Sander]

LGTM, I like the new approach.

Couldn't initialize be synchronous now? void initialize(...)

[nilsreichardt]

Couldn't initialize be synchronous now? void initialize(...)

Yes, good catch!