Amazon Web Services

Amazon Web Services provides the full cloud stack — compute, storage, databases, networking and hundreds of managed services.

Its breadth is both the reason to use it and the reason it is hard: almost anything is possible, and the same result can be built five different ways with very different costs.

Billing is the recurring trap. Charges accrue per resource with no default ceiling, so setting billing alarms before deploying anything is a practical necessity rather than a precaution.