The 90-Second Interface
Designing Pulse forced a rule I hadn't worked with before: every session must complete in under 90 seconds. Here's what that constraint broke open.
The brief had one weird clause.
When the Pulse founder handed me the brief, everything was standard until the last line: 'All user sessions must be completable in under 90 seconds.' Not 90 seconds as a goal. As a hard constraint. Users were high-stress professionals — lawyers, surgeons, early-stage founders. They didn't have time for a 10-minute meditation. They needed something they could do in a elevator, or between meetings, or in a bathroom stall at a conference.
90 seconds broke every pattern I knew.
Standard mobile UX patterns assume time. Onboarding flows assume 3–5 minutes. Content exploration assumes browsing. Progress systems assume multi-day loops. None of that works when the max session is 90 seconds. I had to throw out most of what I knew about mobile UX and design from constraint.
When you can only ask a user for 90 seconds, every second has to earn its place. Ornamentation becomes disqualifying.
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What the constraint forced
One action per screen.
The first cut was aggressive: no screen can have more than one thing to do. Not one primary and one secondary. One. This is harder than it sounds when you're conditioned by apps that layer options as a feature, not a bug. Every time I added a 'maybe they'd also want to…' element, I cut it. The density came down. The clarity went up.
I kept a running count of actions per screen during reviews. Anything above 1.2 average went back for rework.
[POINTING]I kept a running count of actions per screen during reviews. Anything above 1.2 average went back for rework.
[POINTING]One-handed use wasn't a nice-to-have — it was required. These users were often holding something else. A coffee. A laptop. A kid. All interactive elements had to be reachable with a right thumb in the bottom 40% of the screen on a standard phone. This completely changed the information hierarchy. Navigation moved down. Content moved up. Primary actions sat at natural thumb rest position.
Most apps are designed for someone sitting at a desk with two hands and nothing better to do. Pulse is designed for someone who has approximately 90 seconds before their next meeting starts.
Haptics became a design material.
When screen time is at a premium, every feedback channel matters. Haptic feedback let us confirm actions without a confirmation screen. A soft tap on session start. A distinct double-pulse on completion. Users could feel the session arc without looking at the interface. This was the highest-leverage accessibility win we shipped — it also happened to make the experience feel genuinely premium on devices that support it.
Outcomes from the constraint
Designer and builder — I prototype to learn what's possible, then refine until it ships. Systems-thinking, hands-on builds, and interfaces people remember.
