Question: Is DynamoDB PaaS or SaaS?

Answer

DynamoDB is a database as a service (DBaaS), which most cloud taxonomies file under platform as a service (PaaS), not software as a service (SaaS). AWS describes it as a serverless, fully managed NoSQL database: you create a table and call an API, and AWS runs the servers, storage, replication, patching and scaling behind it.

Why it isn't SaaS. SaaS is a finished application that end users sign in to, such as Gmail or Salesforce. DynamoDB is a building block for developers. You use it from your own code through the AWS SDKs, the AWS CLI or its HTTPS API.

Why it's more managed than classic PaaS. Many managed databases still ask you to pick instance sizes, storage volumes, engine versions and maintenance windows. DynamoDB has none of those. There are no instances or clusters to size, and in on-demand mode, the default, you don't even set throughput: you pay per request plus the storage you use. Encryption at rest is always on.

What you still own. Under the AWS shared responsibility model, you're responsible for:

• the data model: keys, indexes and access patterns
• IAM permissions and resource-based policies
• the capacity mode and, for provisioned tables, capacity and auto scaling settings
• backups, such as turning on point-in-time recovery
• what you store, for example encrypting sensitive fields on the client

What is DynamoDB? covers the basics, and DynamoDB capacity modes explains on-demand versus provisioned billing.

Source: AWS DynamoDB documentation.