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Android conference companion for schedules, maps, news, and more.

Companion apps: iOS · Web

Stack

• Kotlin, Jetpack Compose, Material 3
• Firebase (Firestore, Auth, Messaging, Crashlytics)
• Koin, Coroutines, Navigation Compose

Architecture

The app uses a pragmatic MVVM + repository layout across Gradle modules. Data flows like this:

Compose screen → ViewModel → repository → :data interface
  → Firebase / Retrofit implementation → :core model → Flow → UI

• :core — shared domain models, utilities, and networking primitives. No project dependencies.
• :data — backend-neutral data-source interfaces (and a few local bookmark implementations). Depends on :core.
• :ui — shared Compose screens and components used across features. Depends on :core and :feature-glitch.
• :app — composition root: DI, navigation, most repositories/ViewModels, and screen wiring. Depends on every module.

Feature isolation varies: some modules own repository + ViewModel + UI (feature-merch, feature-locations); others are mostly UI shells or infrastructure. Navigation and Koin bindings are centralized in :app.

Dependency graph

:core
├── :data
├── :feature-glitch ──→ :ui
├── :feature-play ──→ :feature-firebase
├── :feature-analytics
├── :feature-reminder
├── :feature-retrofit
│
:data + :ui
├── :feature-locations
├── :feature-merch
├── :feature-documents
├── :feature-feedback
├── :feature-organizations
├── :feature-wifi          (:core + :ui only)
│
:app → all of the above

Foundation

Module	Role
core	Domain models (Conference, Event, Speaker, …), shared state types, OkHttp client, notifications, storage helpers
data	Data-source contracts (ContentDataSource, LocationsDataSource, …) plus local bookmark stores
ui	Reusable Compose screens/components (schedule, home cards, maps chrome, settings, filters) and shared UI state types

Infrastructure (feature-*)

Module	Role
feature-firebase	Primary backend: Firestore data sources, DTO → core mapping, anonymous auth / conference session
feature-retrofit	HTTP maps download/cache (MapsDataSource)
feature-analytics	Analytics events and Remote Config flags
feature-play	In-app updates and Play Age Signals
feature-reminder	WorkManager-based event/feedback reminder notifications
feature-glitch	Visual/easter-egg effects consumed by :ui

User-facing features

Module	Role
feature-locations	Location tree browser (repo, ViewModel, screen)
feature-merch	Merch catalog, cart, and order-summary QR
feature-documents	Conference document list/detail
feature-feedback	Feedback form UI and HTTP submission
feature-wifi	Wi-Fi join helpers and screen (ViewModel lives in :app)
feature-organizations	Org list/detail UI (repo/ViewModel live in :app)

Composition root (app)

App initializes Firebase, Timber, and Koin. AppModule binds every :data interface to a concrete Firebase/Retrofit implementation and registers repositories and ViewModels.

MainActivity owns the root NavHost; route wrappers in :app collect ViewModel state and pass it into :ui or feature screens. Feature modules do not register their own navigation graphs.

Requirements

• Android Studio Ladybug or newer
• JDK 17
• minSdk 26 / targetSdk 36

Place app/google-services.json for Firebase before building.

Build

./gradlew :app:assembleDebug

Install on a device or emulator:

./gradlew :app:installDebug