Hit 429 Too Many Requests when ramping JMeter 5.6.2 to 60 threads from Singapore. Single requests pass fine. The architect flow hangs then fails under load. Using platform_api with OAuth token. The outbound contact creation payload below:
{
"external_contact_id": "test_001",
"campaign_id": "abc-123"
}
Why is the edge rejecting valid requests at this volume? Need help tuning thread count.