Decisions & Rationale

This section summarizes the why behind key architectural choices. For full detail, see the ADRs.

• ECS + Fargate over EKS: reduce operational overhead while retaining container benefits.
• Aurora PostgreSQL as system of record: transactional correctness and row-level locking.
• SQS + workers for fulfillment: resilience under retries/failures; keeps webhooks fast.
• Stripe Checkout + webhooks: minimize PCI scope; safe, idempotent payment lifecycle.