Welcome, and thanks for taking the time. This is a short, focused exercise (target: 3–6 hours total) to see how you read unfamiliar code, debug, and finish a small feature on native Android and iOS.

There are two tiny apps in this repo — one Android (Kotlin/Jetpack Compose) and one iOS (Swift/SwiftUI). They are partially complete: each one builds and runs, but neither works correctly yet. Each app contains a few intentional bugs and one unfinished feature. Your job is to get both apps behaving as described in the spec below.

Both apps are the same product, built natively on each platform:

1. Fetch a list of articles from a remote JSON endpoint on launch.
2. Display them in a scrollable list, showing each article's title and body.
3. Let the user bookmark / un-bookmark an article by tapping a bookmark control on each row. The bookmarked state must be visibly reflected in the UI immediately and persist while the app is running (in-memory is fine).
4. Handle the loading and error states gracefully (a spinner while loading, and a readable message + retry if the request fails).

Both apps read from this public mock endpoint (no auth, no key needed):

https://jsonplaceholder.typicode.com/posts

It returns a JSON array of objects shaped like this:

[
  {
    "userId": 1,
    "id": 1,
    "title": "sunt aut facere repellat provident",
    "body": "quia et suscipit\nsuscipit recusandae..."
  }
]

Treat each object as an Article: use id, title, and body. You can ignore userId. (There is no "bookmarked" field in the data — bookmark state lives only in the app.)

No internet? A copy of the payload is included at mock/articles.json. See that folder's note for how to serve it locally and point the apps at it.

This exercise is deliberately small. We care much more about how you work than about volume:

• You can find and fix the bugs, and you understand why each one was a bug.
• You complete the bookmark feature so the UI updates correctly and reliably.
• Your fixes are idiomatic for the platform (state management, threading, serialization, app configuration).
• Clean, readable diffs. Small, sensible commits beat one giant commit.

You are not expected to redesign the UI, add a database, write exhaustive tests, or add new screens. If you finish early and want to show off, see Bonus below — but the core fixes come first.

• Open the android/ folder in Android Studio (Koala / 2024.1+).
• Let it sync Gradle, then run on an emulator or device (minSdk 24).
• Entry points to read first: ArticleViewModel.kt and ArticleListScreen.kt.

• Open ios/ArticleReader.xcodeproj in Xcode 15+.
• Run on any iOS 16+ simulator.
• Entry points to read first: ArticleListViewModel.swift and ArticleListView.swift.

1. Fork or clone this repo.
2. Commit your work in logical steps with clear messages.
3. Fill in SUBMISSION.md — a short write-up of:
   • each bug you found and how you fixed it,
   • how you implemented the bookmark feature,
   • anything you'd improve with more time.
4. Send us a link to your repo (or a zip).

The write-up matters: a clear explanation of a bug you couldn't fully solve is worth more to us than a silent fix.

Pick at most one — these are optional signals, not requirements:

• A unit test for the bookmark-toggle logic.
• Persist bookmarks across app restarts.
• A "Bookmarked only" filter toggle.

Good luck