Twilio for SMS, SES for email, both for less.

The "Twilio for everything" decision had been about consolidation: one vendor, one API, one bill. The bill turned out to be the issue. For SMS, Twilio remained the best answer; for email, SES at a tenth of the cost was a better fit at the company’s scale.

We moved transactional email — order confirmations, password resets, receipts — to SES, with Pinpoint holding the templates and audience segmentation that had been in Twilio. SNS handled the backup-notification path. SMS stayed on Twilio.

Bill dropped 42% net. Email deliverability stayed at the previous baseline (99.4% to inbox at large providers). The team kept the abstraction layer for messaging so future channel changes are configuration, not code.