Creator: Enrico Tartarotti · Published: 2026-03-27 · Length: 15:18 · Watch on YouTube

Your phone waits 100 milliseconds every time you touch the screen. It's deciding: are you scrolling or tapping? (from the video description)

A standalone essay on core input, the one interaction a device is built around, and how prioritizing scroll over click shaped every app on your phone. Sponsored by OpenArt (OpenArt Worlds). Written by Enrico Tartarotti; produced by Enrico Tartarotti and Bartek Malinowski; edited by Seequence.

Summary written from the auto-generated captions, the creator's chapter markers and sampled frames. The captions spell the Apple designer as "Bass" in one place and garble the infinite-scroll inventor's name ("As their asking"); the correct names are used below.

1) Detailed outline

[0:00] The secret behind tech

• Spotify on desktop vs. phone: to queue a song on desktop you open the three-dots menu, hunt through a list and click "Add to queue." On the phone you just swipe the track, and it feels much better.
• Enrico says the reason you spend hours scrolling on your phone isn't simply that social media is addicting: try scrolling Reels on a computer and the same content doesn't feel as good.
• A 100-millisecond difference, decided long ago, became one of the most important decisions in tech history, and no one talks about it.
• Every device is defined by one core interaction. It's what made smartphones the most successful tech device ever, why everyone hates smart TVs, and how you can predict which future products will succeed or fail before launch.

[1:25] Mobile vs. desktop design

• Google Photos: on desktop you click arrows to move between photos and can't drag with the mouse; you click the three dots and then Details to see image info. On the phone you swipe sideways, swipe up for details and swipe down to go back.
• Spotify's player: swiping changes songs and feels better than next/previous buttons; scrolling down reveals lyrics, artist info and events.
• Desktop versions always have more buttons, drop-downs, scroll bars and symbols.
• Consumption vs. creation: when did you last create something real on your phone, like a document, a presentation or a properly formatted email? The phone feels made for consuming and the computer for creating, and nobody decided that on purpose.

[2:50] Dispelling myths

• Myth 1, screen size: the Teenage Engineering OP-1 synthesizer has a tiny screen but is used by famous musicians to produce major hits. The YouTube channel Red Means Recording makes full tracks on it. Its colored knobs make the small interface work brilliantly.
• Myth 2, fat fingers: fingers are imprecise, so mobile needs bigger targets, like having a giant mouse cursor. But before the iPhone there were stylus phones, and Nokia even shipped a phone with a guitar-pick stylus in the box. Input was precise and the interfaces looked like tiny desktop ones (he shows an old Windows phone), and they were bad.
• So it's neither the screen nor the finger; it's something deeper.

[4:16] The 100 ms decision

• Tap something on your phone and it opens. Put your finger down and move it a little and it scrolls. So the phone isn't registering a tap when your finger lands; it waits to see if a scroll starts, and only if your finger stays put does it count as a tap.
• Android is open source, so you can see it in ViewConfiguration.java on android.googlesource.com: tap timeout is 100 ms, and touch slop is 8 dp, the distance your finger can travel before it counts as a scroll. The file reads "Copyright 2006, the Android Open Source Project."
• iPhone works the same way. Its code isn't public, but the delay is generally agreed to be about 150 ms.
• The key: scrolling comes first and tapping comes second. This explains why smartphones won, why mobile apps look the way they do, why you lose hours to Instagram and TikTok but not on your computer, and why phones became consumption devices.

[6:04] Scrolling as control

• In Google Photos on the phone, the arrows and buttons are gone: when scrolling is the main interaction, the screen itself becomes the control.
• Draggable carousels on websites feel clunky with a mouse because on computers the click comes first and scrolling second. Trackpads blur this a little, but interfaces are still built for clicking. Look at a mouse: the primary and secondary actions are obvious.
• On a YouTube video on mobile you instinctively drag the red playhead; on desktop you click where you want to go. Gmail, Amazon and Google Maps show the same split.

[7:05] History of mobile scrolling

• In the early 2000s Steve Jobs was walking through Apple's lobby when a candidate who'd just bombed his interviews showed him a laptop demo of Dock icons that magnify on hover. Jobs hired him on the spot. That was Bas Ording, and the demo is still the Mac Dock today.
• Years later, Apple was secretly building a phone but was stuck. Coming from the iPod, their best idea was scrolling through contacts with a click wheel: better than old phones, but not enough.
• Jobs challenged Ording to build a demo with a screen and no buttons, just a list of names to move through and pick someone to call. What he built was inertial scrolling, which got cheering and applause when it was unveiled.
• Apple patented it. When Samsung copied it, Apple sued for about a billion dollars, and Jobs personally told Samsung, "Here's something we invented. Don't copy it. Don't steal it." He understood that the scroll was the foundation of the whole device.

[8:28] The addictive nature of gestures

• Instagram on the phone: you scroll, a photo appears, a Reel plays, another, another. You don't tap or choose anything, and 40 minutes go by. On the browser you can scroll with a trackpad or mouse, but it isn't the same; YouTube Shorts on desktop even has up and down buttons. Same app, same content: you lose 40 minutes on one device and close it after five on the other.
• Scrolling is a more natural gesture than clicking, but it supports only a few actions (up, down, maybe drag an object). Desktop can show 30 buttons at once; mobile can't.
• You can build clever gestures, like swiping across profile pictures in Gmail to switch accounts, but most people don't know they exist.
• Scroll-based input gives you one to four actions that feel incredibly natural; click-based input gives you many more, less naturally. That's why Apple replaced the home button with a swipe.
• Over time, things once done by tapping were turned into scrolls that are even more addictive: pull to refresh replaced the refresh button, and infinite scroll replaced pages one, two and three.
• Aza Raskin, inventor of infinite scroll, said what he regrets most is not packaging the invention with the philosophy for how it should be used. Loren Brichter, who invented pull to refresh, said smartphones and pull to refresh are addictive, and that with two kids he regrets every minute his phone has him sucked in.
• That's also why kids pick up phones so easily: a few key actions, all done with a natural scroll, with little precision needed.
• Conclusion: it's not the screen size or your fingers; every mobile interaction is designed around scroll being more important than tap. And every device is its core input, which lets you predict success or failure.

[10:40] Sponsor: OpenArt Worlds

• Enrico uploads an image and OpenArt Worlds turns it into a fully navigable, interactive 3D world you can walk or fly through, generating high-quality images of what you see.
• He compares it with The Volume, the real-time projection stage used on Star Wars: The Mandalorian, and Avatar's virtual sets, which cost millions; now any creative can do something similar from one image.
• He drops in a photo from Livigno, one of his favorite ski spots, and walks through it with the keyboard like a video game, with consistent lighting and style. Try it free at openart.ai/worlds.

[12:28] Broken interfaces

• Smart TVs: everyone hates them, and not just because they're slow. Their rows of thumbnails and horizontal category lists were designed for scrolling, but you control them with four arrows and a button: down, down, right, right, right, select. The on-screen keyboard is worse. Smart TV remotes came straight from regular TV remotes, so the interface is built on a broken core input, like stretching a mobile app onto a computer.
• Apple TV tried to fix this in 2015 with a remote that had a touch surface; everyone hated it, and Apple went back to buttons. You can't transplant one device's core input into another.
• Humane AI Pin: with its projector and clunky gestures, which looked clunky even in the demo, the core input was clearly broken, so there was only one way it could end.
• Meta Neural Band for the Meta Ray-Ban Display glasses: everyone who tried it, Enrico included, saw how natural the input is. It's a niche first-generation product, but with a strong core input it could succeed.

[13:53] The future of interaction

• User interfaces have been the main way we use technology for 30 years, but now we spend lots of time typing prompts to chatbots, and the same rule applies.
• Open Claude or ChatGPT and you see just a text box. Old text boxes were unforgiving and demanded perfect input; this one accepts typos, malformed requests or a minute of rambling into the mic, and it still works. It clicked with everyone because the core input works.
• You don't need a settings menu if you can say "make this shorter," or search filters if you can describe what you want. That beats clicking through 40 sub-menus.
• Outro: we have AI chats replacing jobs and billions spent on products nobody uses, yet AirDrop and printers still don't work well. Tech runs at two speeds because of "one of the weirdest laws" deciding how tech gets built, covered in the end-screen video (not named in the captions).

2) Things mentioned

Core interaction-design ideas

• Core input: the single primary interaction a device is built on; Enrico says every device is its core input.
• Tap timeout and touch slop: Android's 100 ms wait and 8 dp movement threshold for telling a tap from a scroll; about 150 ms is the commonly cited iPhone figure.
• Scroll-first vs. click-first design: mobile prioritizes scrolling and the screen becomes the control; desktop prioritizes clicking with buttons and menus.
• Inertial (momentum) scrolling: Bas Ording's no-buttons contact-list demo that became the iPhone's foundation.
• Pull to refresh and infinite scroll: tap actions turned into scrolls, making feeds more addictive.
• Consumption vs. creation devices: phones for consuming, computers for creating, as a side effect of core input.
• Forgiving natural-language input: the AI chat text box and voice dictation as a strong new core input.

Devices and hardware

Apps and services

Film, sponsor and other references

Companies

• Apple, Google (Android), Samsung, Meta, Humane, Nokia, Microsoft (Windows phones), Teenage Engineering, Spotify, OpenArt, Anthropic and OpenAI (Claude and ChatGPT).

3) Biographies

Enrico Tartarotti (host, writer, producer)

Italian-born tech creator and designer behind the YouTube channel Enrico Tartarotti, where he goes behind the scenes of the design, psychology and stories of everyday tech. He's building Flask (flask.do), a video collaboration tool, offers one-hour calls through enricotartarotti.com, and handles sponsorships through Rakugo Media. In this video he says he builds tech for a living and has tried Meta's Neural Band himself. He's on X as @EnriTarta and on Instagram as @enritarta.

Crew

• Bartek Malinowski: co-producer of this video.
• Seequence: the editing studio credited for the video.

People referenced

• Bas Ording: Dutch-born interface designer who joined Apple in the late 1990s and worked there for about 15 years on Mac OS X and iPhone interfaces. He's credited with the magnifying Dock animation and the iPhone's inertial scrolling and "rubber-band" bounce, and is named as an inventor on many Apple patents, including ones at issue in Apple v. Samsung. The video tells the story of Jobs hiring him on the spot after a Dock demo.
• Steve Jobs (1955–2011): Apple co-founder and CEO who led the iPhone's development; in the video he challenges Ording to build a buttonless contact list and later confronts Samsung over copying it.
• Aza Raskin: American designer and technologist credited with inventing infinite scroll around 2006, later a co-founder of the Center for Humane Technology, where he speaks about attention-harvesting design. The captions garble his name.
• Loren Brichter: American software developer who created the Tweetie Twitter app, where he invented pull to refresh, later acquired by Twitter. He has publicly said he has mixed feelings about how addictive the gesture made phones.

Organizations referenced

• Apple: maker of the iPhone, Mac and Apple TV, and owner of the scrolling patent.
• Samsung: Korean electronics maker that Apple sued over copied iPhone features.
• Android Open Source Project (Google): publishes the Android framework code where the 100 ms tap timeout is visible.
• Teenage Engineering: Swedish maker of the OP-1 synthesizer.
• Humane: startup behind the AI Pin wearable.
• Meta: maker of the Ray-Ban Display glasses and the Neural Band wristband controller.
• OpenArt: AI image platform whose Worlds feature sponsors this episode.