Managed Databases at Scale

Don't manage your own DB on a VM. Use Platform-as-a-Service (PaaS). The cloud provider handles backups, patching, and high availability so you can focus on your data.

1. Azure SQL / AWS RDS

Managed Relational databases. You get 99.99% uptime and **Automatic Scaling**. You can even enable 'Serverless' mode where the DB turns off when no one is using it, saving you 80% on costs.

2. Cosmos DB / DynamoDB (NoSQL)

Designed for Infinite Scale. Cosmos DB can replicate your data across 50 regions globally with <10ms latency. It is the choice for global applications like Uber or Netflix.

4. Interview Mastery

Q: "When would you choose a 'Provisioned' vs 'Serverless' database?"

Architect Answer: "I choose **Provisioned** for predictable, steady traffic (e.g., an internal company app). It is cheaper and avoids 'Cold Start' latency. I choose **Serverless** for unpredictable traffic (e.g., a startup) or for dev/test environments. It scales to zero when not in use, which is much more cost-effective for irregular workloads."