Lesson 1 / 25
How AI Features Differ From Ordinary Features
Quality is a distribution, not a pass/fail.
Five differences
A normal feature either works or throws an error. An AI feature (summaries, chat, classification, drafting) produces varied outputs whose quality spreads across a range; most are fine, some are wrong, a few are harmful. It can change behaviour when the provider updates a model or when you edit a prompt. Its cost scales with usage and output length. Users may over-trust fluent but wrong answers. And misuse (prompt injection, jailbreaks) is part of the threat model. A rollout plan must handle all five.
Probabilistic features, real consequences
AI features fail in fuzzy, varied ways, so launches need explicit metrics, bars and exit routes.
Ordinary versus AI feature launches
What changes in the plan.
aspect ordinary feature AI feature
correctness pass/fail tests quality distribution, sampled review
changes only when you deploy prompt edits, provider model updates
cost mostly fixed per request, grows with usage and length
failure visibility errors, crashes plausible wrong answers, silent
abuse standard security + injection, jailbreaks, data leakagePlan for the bad tail
Assume a small share of outputs will be wrong or unsafe and design how you detect, limit and recover from them.
Quick check: Why is "it passed QA" not enough for an AI feature?
- QA cannot run AI code
- AI features never fail
- Outputs vary, so quality must be measured as a rate across many cases
- Tests make models worse
Answer
Outputs vary, so quality must be measured as a rate across many cases — Measure distributions, not single passes.