How do you implement data preloading in case of slow API performance?

I use the following approaches:

• Caching:
  • Caching data at the application level (Shared Preferences, Room Database).
  • Using HTTP caching via OkHttp.
• Offline mode:
  • Saving received data for later display without re-requesting from the API.
• Background loading:
  • Using WorkManager or Coroutines for asynchronous data loading in the background before it is needed by the user.
• Progressive rendering:
  • Displaying partially loaded data or placeholders during full data loading.
• Data quantization:
  • Breaking large requests into smaller ones for faster loading and display.
• Network request optimization:
  • Data compression.
  • Using Protobuf instead of JSON for data transfer.
  • Applying prefetching of relations (e.g., in GraphQL-based APIs).

Example of using Coroutines for background loading:

// suspending function for data loading
suspend fun loadDataInBackground(): List<Item> {
    // Simulate slow loading
    delay(2000) 
    // API call here
    return listOf(Item("Item 1"), Item("Item 2")) 
}

// Launch background loading at Activity/Fragment start
lifecycleScope.launch(Dispatchers.IO) { 
    val data = loadDataInBackground()
    // Handle received data on the main thread
    withContext(Dispatchers.Main) { 
        updateUI(data)
    }
}

data class Item(val name: String)

fun updateUI(data: List<Item>) {
    // Update UI with preloaded data
}