AWS now offers over 30 AI and ML services. The breadth is impressive — but it also means teams frequently pick the wrong tier, over-engineer solutions with SageMaker when a pre-trained API would suffice, or under-invest when custom models are actually needed.

This guide maps every AWS AI service into a decision framework: three tiers based on how much control (and responsibility) you want, with clear guidance on when each service fits.

The Three-Tier AWS AI Stack

┌─────────────────────────────────────────────────────────────────┐

│ Tier 3: PRE-TRAINED AI APIs (No ML expertise needed) │