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Production reliability · ChatDaddy

Fixing decryption failures in retried WhatsApp messages

Investigated a high-failure retry path and improved message handling, taking decryption failures from 65% to under 1%.

retry decryption failures, down from 65%<1%

01 · Context

What needed to change

ChatDaddy manages 10M+ messages daily across its channels, including 4M+ WhatsApp messages. Retried WhatsApp channel messages had a separate decryption failure problem that affected recovery after delivery issues.

02 · Challenge

The hard part

The fix had to address the retry path without introducing regressions into the broader messaging flow.

03 · Approach

How I approached it

  1. Investigated the failure pattern specifically in retried WhatsApp channel messages.
  2. Updated the backend handling for retries and checked the result against production failure rates.
  3. Used operational evidence to separate this failure from unrelated messaging issues.

04 · Outcome

What shipped

Reduced decryption failures for retried WhatsApp channel messages from 65% to under 1% in a WhatsApp system handling 4M+ messages daily within a 10M+ message-per-day platform.