Cloud

The flat-namespace key/data/metadata model behind S3 and GCS — no real folders, no in-place edits.

EBS, EFS, and S3 side by side — three fundamentally different interfaces for three fundamentally different access patterns.

Two different math-based strategies for surviving disk failures — full copies versus data-plus-parity chunks.

Standard, Infrequent Access, and Glacier — trading cheaper storage for slower, sometimes costlier retrieval.

A Lambda function that opens its own database connection scales beautifully — right up until it takes the database down with it.

Storage looks cheap on the pricing page — until the bill for data leaving the cloud arrives.

Once petabytes of data and years of tooling accumulate around one cloud provider, moving it becomes structurally hard — not just expensive.