Lesson 3.3 · D3 Product & Model Selection · 4 min
Align model choice with cost, speed and quality
Weigh volume, latency, complexity, stakes and frequency.
What the exam tests
Justifying a choice in a scenario, often by spotting the factor that dominates.
Key ideas
- Volume and latency
- Thousands of items a day, or results needed in real time, push towards faster tiers.
- Complexity and stakes
- Long, nuanced material or decisions with major consequences push towards more capable tiers.
- Frequency
- A one-off, high-stakes synthesis can justify a higher cost per use; a daily batch multiplies every cost.
- Review changes the calculus
- If people review every output anyway (for example suggested replies), a faster tier often gives the best value.
- Test on a sample
- Compare tiers on representative examples before committing a workflow.
Common traps
- Ignoring volume when picking a tier for a batch job.
- Picking by name or the CEO's preference.
Remember
Find the dominant factor: volume and speed, or complexity and stakes.