Bits of .NET

This looks innocent:

await Task.WhenAll(requests.Select(r => ProcessAsync(r)));

But if requests = 10,000 items →
you just spawned 10,000 concurrent tasks.

✅ Safe Pattern

using var semaphore = new SemaphoreSlim(10);

await Task.WhenAll(requests.Select(async r =>
{
    await semaphore.WaitAsync();
    try { await ProcessAsync(r); }
    finally { semaphore.Release(); }
}));

Why this matters

• Prevents thread starvation

• Protects downstream services

• Stabilizes latency under load