Avoiding "Zombie UI": Katie Dill on Keeping Intent and Craft Alive in the AI Building Boom

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Overview

Katie Dill of Stripe opened her talk at the Lenny and Friends Summit with a history lesson about architecture. She argues that the AI boom closely resembles the building boom that followed World War II, and that if builders aren't careful, the result will be the software equivalent of that era's generic buildings. Her question is how to use AI to build products that have care, character, and soul rather than monotony. She answers with three warning signs and four recommendations drawn from Stripe's own work.

18 min read
0:14

The Post-War Building Boom and the Birth of "Zombie Buildings"

Right after World War II, Dill explained, there was a massive building boom, which she called the largest in history. In the US, people were coming home from the war, new technologies and construction methods were available, and buildings went up quickly. The builders of that era borrowed modernism from the 1920s: simple geometries, clean bare surfaces, monochromatic palettes, and no adornment.

Dill was careful to credit the original modernists. Whatever one thinks of the style, she said, its founders had intentionality. There was a point of view behind the Villa Savoye and principles behind the Bauhaus. After the war, though, the urgency to build and the new methods meant the style was copied again and again without that intentionality. "The thinking got thinner and thinner," she said, until all that remained were generic patterns poorly suited to their context.

Her example was banks. Banks once had architecture that signaled trust, reliability, and security. They were replaced by anonymous boxes, a pattern she says has continued to this day. She calls them "zombie buildings." Nothing differentiates them and nothing signals that they were designed for their purpose. In her view they show no care for users, for the people living around them, for context, or for brand.

2:14

Three Watch Points for the AI Building Boom

Dill thinks about this often because people are surrounded by such buildings and because we are now in another boom: the AI building boom. "Everybody and their mother can build now," she said, and teams of three can do what used to require teams of thirty. She sees echoes of the post-war period and described three "watch points."

The first is that LLMs are very good at producing the most probable answer. In her framing, that means they are good at telling you what has been popular, what has worked, and what was in style. They are less good at producing something original or specific to your brand and your users' context. To illustrate, she showed a website and asked the audience to guess what the company sold. Software? No, Korean barbecue. She allowed that it was probably a fine website, but said it had no character and no connection to the user or the context in which it would be used.

The second watch point is what she called "the temptation of done." AI makes things feel finished very quickly, often too early. Her example was her own habit of eating a microwave burrito for lunch. She takes a frozen rock out of the freezer and 90 seconds later has lunch. The result is "nearly inedible," she admitted, but she is so taken with the speed that she overlooks serious flaws. She sees the same thing happening with AI. You type a sentence and get an interface with nice rounded corners and drop shadows, and it feels good enough to ship. That polished surface can mislead, she warned. Does it actually solve the problem? Does it differentiate? She noted that the questions Claire Vo raised earlier at the summit apply here.

The third watch point is disposability. Because this work is so quick and easy, it often feels disposable and gets treated that way. People can let responsibility for their decisions slide and stop thinking about the long term, including who will maintain what has been built.

Dill said that together these three forces could produce a world like a real place in Turkey, which she showed as an image of repetitive, undifferentiated construction. The software equivalent is what she calls "zombie UI": patterns that don't fit their context and that are monotonous, vacant, or uncared for.

4:52

What Cared-For Software Looks Like

People spend half their waking lives looking at screens, Dill said, so they want software that feels cared for. She gave several small examples. One was the Grok bot's little animation and the sense of life it adds. Another was calendar apps that show the actual date on their tab icon. Users click past this detail all day, she said, but it shows the builder cared about them.

A third example was about understanding context: Stripe's Link agent wallet. According to Dill, it anticipates problems an agent might run into while buying online and includes troubleshooting for them, because the team thought about the user's context even when that user is an agent. For her, these examples show builders who care about their users and put that care into the work, and they reveal a brand's character, or soul. She believes AI can help achieve this, even though it is sometimes the cause of the problem.

5:56

Recommendation One: Have a Point of View

Her first recommendation is to have a point of view, because "if you don't, AI will give it for you." Given the first watch point, that borrowed point of view will probably be generic and backward-looking. Teams need to define their brand: what it means to them, what it means to users, who they want to be for those users, and what those users care about. She says this becomes the basis of a team's standards.

She said she would give this advice in any era, but it matters more now. When building is distributed, ownership becomes diffuse. More people contribute to products in more ways than before, and handing decisions over to AI is easy. At Stripe, she said, the company cares a lot about optimism and tries to express it in details large and small: color choices, writing style, the topics it writes about, and products built to support entrepreneurs. Because so many people contribute and so much is changing, being aligned on these details matters.

She described a recent design crit that showed what happens when alignment is missing. The team was reviewing an ad that combined Stripe's parallelogram brand mark with users' visuals. The general idea came through, but some things were off. A cross-functional partner in the room who wanted to move fast and ship asked what Dill called a curious question: what is the quality standard for something made with AI?

Dill's answer was that how something was made shouldn't matter. Users don't care about the method. They care whether the result is good, and so should the team. The discussion produced alignment on what mattered, and the team left with 17 bullet points of improvements: some frost here and there, softer edges, slightly smaller bubbles. According to Dill, the office now uses "Pepsi bubbling" as a verb for this kind of meticulous craft. She said the goal isn't perfection. It is to go one level deeper than what the customer can see, because that craft will reach them. A point of view, in her account, drives both the standards and the work, particularly when agents are involved and so much more happens every day.

How do you develop a point of view? Dill said it comes down to getting very good at noticing. Notice what users need and want, not only what they say. Notice what in the world around you signals good, great, or "meh," both in the products you use and in analogous fields, so that art, science, and a broader perspective can inspire the work. Building taste and understanding raises your own standards, which you then have to scale.

9:12

Recommendation Two: Encode Your Standards Into the Machine

Her second recommendation follows from the problem of scale. It would be wonderful, she said, if every person shared the same understanding and made the same decisions. But humans will not be part of every decision from here on. She pointed to interfaces built without a designer present, agents finding and fixing problems overnight, and generative UI created for users in real time.

She says this is why design systems "are having a moment again," although today's system differs from yesterday's. In the past, not everything had to be written down, because a designer was usually present to fill in the gaps. Now systems have to support distributed building and agentic construction, so decisions need to be easier to define. In her words, "the object of design is no longer the screen. It is the system itself."

She illustrated this with Gutenberg. Everyone knows he created the printing press, she said, but fewer people know about the system he built around it. He didn't stop at 26 lowercase and 26 uppercase letters. He made 290 unique characters, including different widths, abbreviations, and ligatures. His goal was fully justified text without the "rivers and lakes" of whitespace that would spoil the finished page. In Dill's reading, he made the system extensible and opinionated enough that machine-made output could feel as good as handmade. That is her target too: "The old system scaled consistency, but the new system needs to scale intent."

She was candid that Stripe is still working this out and has hit snags. The goal is to let builders go from prompt to production almost instantly. Like many companies, Stripe started with an MCP server that understood its design documentation. The results were not good. It wasn't specific enough, it didn't drive the right outcomes, and three people could enter the same prompt and get three different results.

Stripe has since built a CLI on top of its design system. Dill described it as a harness that makes the AI "far more obedient." It lives where builders already work and feeds documentation in at the right time and place, which she said helps avoid context rot. The key difference from earlier design systems is that it includes full templates and flows, not just components and atomic parts. The system therefore knows how the product is supposed to behave and fit together, which makes it much more opinionated than before. Building standards into the means of production, she said, leads to a more coherent product.

She called this only the baseline and quoted Christopher Alexander: "A system can satisfy every rule and still be dead."

12:34

Recommendation Three: Refuse to Confuse Done With Good

Her third recommendation starts from the observation that "the filter is gone." Quality filtering used to be built into every stage of product development, even before a project began. A team might have 20 ideas and staff only one, then poke, prod, and prune along the way so products grew fairly methodically. Now a team can build 20 ideas in a week. Dill sees real benefits in this. Teams can skip theoretical meetings about hypothetical products and react to real things. But the filtering that used to happen throughout the process now has to happen after the build, when saying no is much harder.

This is where she sees the role of the editor, which she called "ultra important." She asked the audience who in their organizations looks at the end-to-end experience and judges whether the result is a coherent whole. She called it a new behavior: people have to unlearn that built means done and that done means good.

Her main advice for improving editing skills is to experience the product as a user would. Does it solve the problem? Does it match how the user thinks? Is it coherent? Many things look good in isolation but feel disconnected once they're assembled into a user journey. She added that editing isn't only a yes-or-no decision. It also means asking whether something is fully formed and how to push it to completion. "We don't want done to be the enemy of good."

She cited an article by Nabeel Qureshi on what makes art great. As she summarized it, greatness comes from unexpected details that make you think "I can't believe they thought of that," from deeper meaning beneath the surface, and from continuous themes that tie the work together. Dill said these are things AI is not good at, and knowing those gaps helps people fill them. She paraphrased Qureshi's point that part of what offends people about AI slop is the sense that the details don't matter: the cup is green, but it might as well have been blue. An editor, she said, takes responsibility for every decision, which in many ways means every pixel.

15:17

A Case Study: 56 Iterations on the Summit's Opening Animation

Dill's team designed the event itself, and she used its opening animation as an example. Stefan, a member of her team, and his colleagues started with a 3D model of the scene and brought it into AI to help with the animations. She showed the first version. It was fun, it moved nicely, and the individual parts were enjoyable to watch. But looked at pixel by pixel, she said, something felt off. The motion wasn't quite right and was a bit jerky, and you wanted to see more of the scene.

So he kept iterating. After 56 iterations, Dill said, he arrived at something truly beautiful, with more realism and more life. The differences were subtle, but she said you could sense the care. What impressed her most was that without AI he might not have attempted such a complex scene or explored so many viewpoints. It wasn't one-and-done, and it took persistence and scrutiny, but in her view AI opened up the possibility space.

16:34

Recommendation Four: Unleash Creativity and Artistry

Dill called her fourth recommendation her favorite. AI can help mass-produce monotony, she acknowledged, but she also called it "the greatest creative catalyst we've ever had." She thinks this matters more now because when everyone is building, differentiating will be both harder and more important.

She argued that today's dominant interfaces, which she listed as chats, charts, and CLIs, are nowhere near the peak of what interaction can be. There is much more to do to make software feel generative, alive, responsive, and dynamic. "We can literally talk to the computers," she said, and urged the audience to branch out and invent new interfaces and new aesthetics. The best practices haven't been written yet, and builders now have the tools to write them. She compared the moment to multi-touch enabling new interactions and the synthesizer enabling new sounds.

She said she sees this happening online: people showing up the Stripe design team with more interesting data visualizations, restaurant websites with character and personality (in contrast to her earlier Korean barbecue example), and people using AI to paint and make art. At Stripe, she said, AI is used to amplify the creative team. The most recent cover of Built to Grow started with a human marbler who produced a series of iterations. The team then used AI to refine the details so the colors and lines were exactly where they wanted them. Dill described this as taking the good judgment of humans and using AI to scale it.

18:47

Tactics: Better Inputs, Tougher Scrutiny of Outputs

To make AI a stronger creative partner, Dill offered two tactics. The first is to improve inputs. Prompts should be more specific and point toward your brand and your particular interests. Instead of simply asking for a website for a Korean barbecue restaurant, explain what you believe in, what good looks like, and what you care about. Add the source material you used to build your own standards, and push the model to think in different ways.

The second is to stress-test outputs. Don't fall for "the burrito dilemma." Push one step further, use adversarial agents to critique the work and rough it up, but keep pushing for better yourself.

19:26

Culture: "Protect the Strange"

Dill said these tactics are the easy part and the harder part is cultural. Following cookie-cutter patterns is safe and comfortable. Finding something unique that improves the status quo is harder and more impressive. Her advice to team leads was not to simply tell people to use AI, but to give them room to explore: "Protect the strange." AI lowers the cost of creating, and she suggested spending some of those savings on making something special. If AI is only used to make the same things faster, she said, teams miss the most interesting part. AI can "raise the ceiling, not just the floor." What matters most, she said, is intentionality: your point of view, your system, your quality bar, and your ambition, brought to life with AI.

20:43

Closing: Gothic Architecture and a Creative Renaissance

Dill closed with a counterexample to post-war modernism: Gothic architecture. She noted that in 1850 John Ruskin wrote extensively about quality and craft and held up Gothic architecture as the epitome of greatness. He observed that no two Gothic buildings were alike, and not even two columns. Each detail was individually crafted and showed the hand and mind of its maker, so the work felt cared for.

That, Dill said, is what users want. They are not impressed that something was animated with Three.js and Blender in 30 minutes. They are impressed when their problems are solved and when clever details show that the builders anticipated their needs and that the brand has character. In this building boom, she concluded, builders can choose not to make the digital equivalent of zombie buildings and can instead make it a creative renaissance, with products that are more powerful and that show the hand and care of the maker.