Bulk user updates hitting 429s despite exponential backoff logic

We’re trying to sync a batch of 500 users from our internal HR system to Genesys Cloud. The goal is to update specific custom attributes via PATCH /api/v2/users/{userId}.

I’ve got a standard Python script using the requests library. I implemented what I thought was a solid exponential backoff strategy. The logic waits for the retry-after header, or defaults to a base delay that doubles on each subsequent failure.

Here’s the core loop:

import requests
import time
import json

def update_user(client_id, user_id, payload, max_retries=5):
 url = f"https://{org}.mygen.com/api/v2/users/{user_id}"
 headers = {
 "Authorization": f"Bearer {client_id}",
 "Content-Type": "application/json"
 }
 
 for attempt in range(max_retries):
 try:
 response = requests.patch(url, headers=headers, json=payload)
 if response.status_code == 200:
 return True
 elif response.status_code == 429:
 # Check for Retry-After header
 retry_after = response.headers.get("Retry-After", 1)
 # Default to exponential backoff if header is missing or non-numeric
 try:
 delay = int(retry_after)
 except ValueError:
 delay = 2 ** attempt
 print(f"Rate limited. Waiting {delay}s...")
 time.sleep(delay)
 continue
 else:
 print(f"Error: {response.status_code} - {response.text}")
 return False
 except Exception as e:
 print(f"Request failed: {e}")
 time.sleep(2 ** attempt)
 return False

The issue is that the 429s keep coming. It’s not just one or two. The whole batch stalls after about 50 updates. I’ve tried adding a fixed 200ms delay between requests even on success, but it doesn’t help. The Retry-After header is usually present, so the script is respecting it.

Environment specs:

  • Python 3.9
  • requests 2.28.1
  • OAuth2 Client Credentials flow (getting a new token every hour)
  • Target: Genesys Cloud US-East
  • Payload size: ~1KB JSON per user

Am I missing something about how the rate limits are calculated? Is there a global limit for the tenant that I’m hitting regardless of the backoff per user? I can’t find clear docs on the specific limits for user PATCH endpoints.

Also, is there a better way to do bulk updates? The POST /api/v2/users endpoint only supports create, not update. I see there’s a PATCH /api/v2/users endpoint that takes an array, but the docs are sparse on the exact payload structure for that one. If I switch to that, do I still need this granular backoff logic, or does the API handle it internally?