Use Concurrent Function for Parallel API Calls

The Problem

When your app needs to fetch data from multiple sources, running API calls one after another can make your app feel sluggish. Each call waits for the previous one to complete.

The Solution: Concurrent Function

The Concurrent function allows you to run multiple operations at the same time, dramatically reducing load times.

Before (Sequential)

// Each call waits for the previous one
ClearCollect(colCustomers, Customers);
ClearCollect(colOrders, Orders);
ClearCollect(colProducts, Products);

After (Parallel)

Concurrent(
    ClearCollect(colCustomers, Customers),
    ClearCollect(colOrders, Orders),
    ClearCollect(colProducts, Products)
)

Performance Impact

If each API call takes 1 second:

• Sequential: 3 seconds total
• Concurrent: ~1 second total (limited by slowest call)

Best Practices

• Use Concurrent in your App.OnStart for initial data loading
• Group related but independent data fetches together
• Don't use Concurrent if one operation depends on another's result
• Combine with loading indicators for better UX

Pro tip: Combine Concurrent with App.StartScreen to show users a loading screen while data loads in the background.