Per its annual habit of releasing the source code for its I/O app a few months after the event ends, Google has done so once again with the 2018 refresh of the app.
Even though the primary purpose of the app is to serve as a scheduler for the event, it has also generally been a good indicator of what's in store for users in terms of the visual aesthetic trend that Google would be following in a given year. Similarly, for developers, the source code of the app would reveal the 'recommended' coding practices, by giving them a peek at how the newest APIs and platforms can be best utilized.
Alongside here is a neat little overview of how the app has been designed to work; rather than follow the traditional ContentProvider + SyncAdapter achitecture that's been followed in the I/O 2017 app, the 2018 one has seen a dramatic ground-up rewrite, following the new Android Architecture Components system, per Google.
The overarching methodology followed in designing the app has also seen rather large changes, with greater emphasis placed on modularity.
Moreover, the dev team for the app has made use of Kotlin, a newer, modern language, to write the codebase of the app itself. If interested, you can check out additional information on Kotlin from over here.
Source: Android Developers Blog