Migrating transactional from SendGrid to Resend: what broke

We moved password resets and billing receipts from SendGrid to Resend. Deliverability stayed stable, DX improved a lot.

What surprised us: webhook payload shape differed enough that we rewrote two handlers. Template migration was manual because we rebuilt in React Email instead of porting HTML.

Would still do it again for a Next.js stack. Just budget a sprint for edge cases, not an afternoon.