Short write‑ups of problems we hit running a real commerce operation and what we changed in the code because of them. No product announcements; just the reasoning.
Fifty‑five kinds of email, one pipeline. How a newsletter to a hundred thousand people is prepared, sent through Amazon SES from a queue, tracked back event by event through SNS webhooks — delivered, opened, clicked, bounced, complained — attributed to the order it caused, and kept from becoming the retry storm that once throttled us at 1,700 calls a second.