Keynote · fictional case

Design for the worst day

The best day is a demo. The worst day is the product.

12 minutes · one idea

3:04 a.m.

A nurse needs the right record in nine seconds.

The system was designed for a training room with good light, fast Wi-Fi, and a full staff. At 3 a.m. it had none of those.

The idea

The worst day is the real product.

Not the demo. Not the happy path. The day the network drops, the data is late, and the person is tired.

Evidence

Three domains, one pattern

Storm

A utility's risk model was accurate — until the map server went down with the power.

Outage

A checkout recovered in 47 minutes; the support script arrived in 6.

Onboarding

A first-run flow lost 18% of users at the one step that needed a human.

The pattern

Stress reveals the system you actually shipped.

Happy path

Designed, measured, demoed. It tells you what the team intended.

Degraded path

Discovered, survived, remembered. It tells you what the product is.

Counterpoint

Delight is not resilience.

A beautiful empty state does not recover a failed payment. A resilient system can still be warm; it just cannot be only warm.

What to do Monday

Three practices, no transformation program

Worst-case walkthrough

Once a sprint, walk the task with the network off, the data late, and the user new.

Degraded-state spec

Every core screen gets an empty, slow, stale, and failed state — designed, not defaulted.

On-call in critique

Invite the person who hears the 3 a.m. page to the design review.

Close

The best day is a demo.
The worst day is the product.

Design for the day you will never put in the launch video.