A company is planning a large event where a promotional offer will be introduced. The company's website is hosted on AWS and backed by an Amazon RDS for PostgreSQL DB instance. The website explains the promotion and includes a sign-up page that collects user information and preferences. Management expects large and unpredictable volumes of traffic periodically, which will create many database writes. A solutions architect needs to build a solution that does not change the underlying data model and ensures that submissions are not dropped before they are committed to the database. Which solutions meets these requirements?