Who is on the other side of the mirror

Customers are people. They lead lives. They have kids, they eat too much, they don't sleep well, they phone in sick, they get bored, they watch too much reality TV. If you're building for some kind of idealized, economically rational buyer, you'll fail. But if you know your customers, warts and all, and you build things that naturally fit into their lives, they'll love you.

— Lean Analytics, A. Croll & B. Yoskovitz

The quote is doing something more precise than a plea for empathy. It is naming a specific fiction: the economically rational buyer, an entity invented for the convenience of models and inherited by product teams who have no idea they are using an economic abstraction as a design brief.

The buyer who never turns up

The rational buyer compares options. Reads the pricing page. Weighs the trade-offs, forms a preference, and acts on it consistently.

Nobody does this. Not because people are stupid — the opposite, in fact. Comparing options properly is enormously expensive in attention, and attention is the one resource genuinely in short supply. Ariely's experiments are useful less for their conclusions about irrationality than for showing how consistently and predictably people substitute a cheap judgment for an expensive one. Kahneman's framing gives it a mechanism: the mind answers a question adjacent to the one you asked, because the adjacent question is answerable now.

So the person on the other side of your flow is not deliberating. They are on a train, on a bad afternoon, with eleven other tabs open, trying to finish something they were asked to finish two days ago. Every screen you build competes with that, and the screen almost never wins.

The mirror

The harder problem is the one in the title, and it is not the customer's. It is ours.

The team knows the domain. It navigates its own product without friction, because it built the paths. It shares a vocabulary, a set of assumptions and a working context with almost nobody outside the building. Alan Cooper's argument, made rudely and correctly in 1998, is that in the absence of an explicit model of a specific user, the implicit model is always the person designing. Not out of arrogance. Out of the sheer availability of oneself.

Which is why the mirror is the right image. You look at the product and see it working. It is working — for the person looking.

Indi Young's version of empathy is the antidote precisely because it is unsentimental. The goal is not to feel what someone feels; it is to build an accurate model of how they reason, including the parts you find irritating. Michele Hansen's contribution is the practical one: the interview technique that gets you there mostly consists of not asking questions that reward the answer you were hoping for.

Plans versus situations

Lucy Suchman's work is the deepest cut here, and it is thirty-five years old. Her argument is that plans are not what generate action. Action is generated by the situation, moment to moment, and the plan is a resource people consult when the situation gets confusing — a rough account, produced before and after, of something that was actually improvised.

For product work the implication is severe. When we design a flow, we are writing a plan and quietly assuming it will function as a script. It will not. It will function as one input among many, competing with a notification, a colleague, a half-remembered instruction and whatever the person was actually trying to do. The user is not executing your flow. They are using fragments of it to get through their afternoon.

This is why the understanding has to come before the building, and why the persuasion added afterwards works so poorly. Onboarding tours assume a person willing to be onboarded. That person exists, occasionally, and is not the median case.

The mirror is worth looking away from — not because your reflection is wrong, but because it is one person, and you are building for someone whose afternoon you will never see.