![[images/The Ridiculous Engineering Of Chat.webp]] **Creator:** Enrico Tartarotti · **Published:** 2026-10-02 · **Length:** 17:51 · [Watch on YouTube](https://www.youtube.com/watch?v=6DSW1rN-ZV4) · Series: *Behind the Product* > *Every chat app you use looks exactly the same… But every tiny difference between them was designed to change how you talk.* — video description ## 1) Detailed outline ### [0:00] Cold open: the two blue ticks - WhatsApp's **two blue ticks** are a **read receipt**. Most chat apps have an equivalent. - When WhatsApp shipped them in **2014**, they were **on by default for everyone**. Users "went crazy": suddenly you could see exactly who was ignoring you, when, and for how long. The backlash was so strong that **10 days later WhatsApp added an option to hide read receipts**. - **[0:32] The clever part is how the switch works.** - On **iMessage** you can hide your own read receipts and **still see other people's**, which is an "unfair advantage." - WhatsApp made hiding **reciprocal**: turn yours off and you can't see anyone else's. Otherwise everyone would turn theirs off with no cost and the feature would die. - **[1:03] WeChat has no read receipts at all, by design.** An internal WeChat lecture is quoted: *if your boss messages you, you read it, and you don't reply, it's trouble.* - Thesis: one tiny tick and one settings toggle shape the behavior (and anxiety) of billions of users, and can be what makes people choose one app over another. ### [1:33] Why "identical" chat apps aren't identical - On the surface every chat app is bubbles, a text box, audio and images. But every decision (bubble position, what Enter does, how delete works) is designed to steer behavior. That's why one chat app fails and another becomes a country's default. - The team spent a month researching and even got on a call with the inventor of the chat UI everyone uses (teaser clip: *"At the time I thought that was a good idea, and then we implemented it."*). - Intro to the show: *Behind the Product*. The story has **three layers**, and only the first is visible. ### Layer 1: Visible UI decisions that shape what you write #### [2:07] Facebook Messenger and the "K" problem - The Messenger team noticed huge numbers of people sending "**K**" to confirm things (back in **2014**; TechCrunch covered it). "K" has since come to read as rude. - The fix: when the text box is empty, the **send button becomes a thumbs-up**, a one-tap acknowledgment. Messenger also let you use it to **react** to messages. - Reactions are now in almost every chat app, and they exist **because pure-text communication got messy and failed.** #### [2:55] The Enter key: email vs. chat - In WhatsApp, iMessage and most mainstream chat apps on desktop, **Enter sends** and **Shift+Enter** adds a new line. In email, **Enter adds a new line**. - That tiny difference is why **emails are long, multi-paragraph and formal (with salutations)** while **chat messages are short bursts**. Multi-line chat writing is *designed to be tedious*: hit Enter by mistake and the half-written message goes out. #### [3:44] Slack: stuck between chat and email - Slack ran **A/B tests**. Unsurprisingly, **Enter-to-send** won as the default, but Slack added a **setting** to choose (Enrico prefers Shift+Enter). - The **always-visible formatting toolbar** signals that this is **more formal communication** than texting. - Inside a **code block the behavior flips**: Enter makes a new line, because that's how code editing works everywhere. Consistency with coding conventions beats immediacy. - **[4:48] Why it matters:** chat apps are really about the *messages people send*, and those can be influenced. - Put Slack's formatting bar in iMessage and it would "fail instantly." iMessage *can* do bold, italic, underline and strikethrough, but showing them permanently would push people toward structured, formal writing. - A **two-line-tall text box** nudges people toward longer, multi-paragraph messages. That's perfect for Slack, which wants important, well-formatted messages while staying closer to chat than email. - These subtleties separate a **billion-dollar product (Slack)** from thousands of failed chat apps. ### Layer 2: What the chat is *actually* for #### [5:51] Instagram DMs are a sharing machine, not a chat - Instagram DMs have everything iMessage has, yet people mostly use them to **send Reels back and forth**. - The **paper-plane share icon** under every post and Reel opens a grid of **friends' faces**: tap one, two, three, send. Inside a chat, every Reel has a **permanent share button**. - DMs were designed as a **sharing engine that feeds the ranking algorithm**. **Adam Mosseri** (head of Instagram): *"One of the most important signals we use in ranking is **sends per reach**."* - That's why Instagram **moved Messages from the top-right corner to the main nav bar**, which angered users. Marques Brownlee clip: *"You used to just swipe over on Instagram and that'll be your inbox. Now you swipe over, it's just Reels."* #### [6:54] WhatsApp forwarding: the opposite goal - WhatsApp also has **Forward**, but you **can't forward to 20 people**: the limit is **5 chats at a time**. Messages forwarded many times get a **"forwarded many times" badge**, and there's a **cap on how often a single message can be forwarded**. - The reason: WhatsApp optimizes for **everyday personal messaging**. Mass sharing there means **spam, scams and chain messages** ("that boomers send to each other"). #### [7:26] Slack vs. Discord: the same features, opposite philosophies - Both have channels, group messages, threads, DMs, sidebar organization and **huddles/voice**. Yet teenagers coordinating **Minecraft redstone builds** won't use Slack, and big companies almost never use Discord for work. - **Replies:** - On **Discord**, a reply lands **inline in the main chat** with a small quote. It's one messy stream, and *the mess is the point*. Threads exist but must be created on purpose and **auto-close (archive) after ~3 days of inactivity**. - On **Slack**, a reply goes **into a thread off the main screen**, with an **"Also send to channel"** checkbox, so every reply is a decision. The channel stays clean for tomorrow's readers. **Slack threads never close** and stay searchable forever. - **[8:28] Presence:** - **Slack** has two states, **Active / Away**, and **decides for you** (about 10 minutes without input → Away). Showing what a coworker is doing would feel like **surveillance**, so presence is minimal and activity-based, which is what matters when you sell to companies. - **Discord** has **four states** including **Invisible** (appear offline), and by default shows friends **what game you're playing or what you're listening to on Spotify**. - *Discord's green dot tells your friends what you're playing. Slack's green dot tells your boss who's there.* - Summary: **Slack is built so messages can be found later**, a company vault that **AI agents can read**. **Discord is built for the present moment**, like walking into a room. ### [9:29] Sponsor segment: Granola - Enrico's team is building an AI **"harness"** (skills plus instructions) for its long, multi-person research process, which mostly happens in hours of weekly calls with producers. - They record calls with **Granola** (AI meeting notes that enhance your own notes with meeting context). Through the **Granola MCP**, their agent (**Claude**) reads all the calls to learn the team's process. That became the foundation for custom **research, fact-checking, drafting and ideation skills**. - Granola MCP plugs into **Claude, Codex or any agent** ("What did we decide about the intro last week?"). The description link gives new users a free first month. ### Layer 3: Why every chat looks the same #### [11:04] The universal layout and its inventor - WhatsApp, iMessage, Messenger and Telegram all share one layout: **others' bubbles on the left, yours on the right, a composer at the bottom, everything scrolling up**. - **Jens Alfke** is "the inventor of the chat UI," and the team interviewed him on a call. - **Comic-book origins (Alfke):** two people facing each other in a panel have balloons pointing left and right. Before that, the state of the art was **terminal-based IRC clients**. - Alfke was into **MUDs (multi-user dungeons)**, a cross between text adventures like **Zork** and RPGs. Around **'97** he started thinking about how to handle chats with many people. - **[12:06]** Put 10 people in a terminal and it becomes a garbled mess, like today's **Twitch chat** (minimal over the stream, but hard to follow). - At **Apple**, while building **iChat** (the video says 1996; Alfke's own sketch is dated 1997 and iChat shipped in 2002), Alfke, who spent his evenings in chat rooms and message boards, struggled to follow many-way chats and **drew a sketch**. On screen: his blog post about rediscovering the **original 1997 ClarisWorks sketch** of a chat UI based on speech balloons. It notes the balloons were later "Aqua-fied" by designer **Steve Lemay**. - Alfke: the hardest technical part was **drawing bubbles behind the text**. Comics were the inspiration, and the **direction of the tail shows who's talking** ("basically a round rect with a triangle sticking out"). - His idea: keep vertical scrolling, **align your messages to the right**, wrap each message in a **comic balloon** to break messages apart visually, and use **color** to tell speakers apart. - Nearly all modern chat, **including AI chatbots and agents**, comes from this. - **[13:11] Earlier "comic chat" was too literal:** some apps had **comic artists draw panels with blank balloons** that didn't correspond to the people at all ("a visual gimmick," a novelty). Alfke's blog notes his design predates **Microsoft Comic Chat**. ![[2026-10-05 06_54_19-.png]] ![[2026-10-05 06_56_19-Greenshot.png]] ![[2026-10-05 06_57_33-Greenshot.png]] #### [13:44] The live-typing experiment that failed and became the typing indicator - iChat experimented with showing a **real-time preview of everything you were typing**, not just an indicator. - Alfke: *"At the time I thought that was a good idea. And then we implemented it… people didn't like it. It gives you this feeling like you're being watched."* Everyone saw every typo, and you could type something inflammatory and backspace over it. - It shipped as a **preference** that most users turned off. What survives is the **typing indicator** (the "…" thought bubble). The video says **Apple still holds a patent** on it. #### [14:49] From desktop to the phone, and everywhere - Before **2007**, **SMS** on phones was mostly a **pile of last-received messages**, not a conversation. - The **first iPhone's SMS app** borrowed **iChat's balloons**. Two years later **WhatsApp** launched with the same thing, followed by **Telegram, Messenger, WeChat and Kakao(Talk)**. - Alfke on seeing it become universal: it took him a while to realize everyone was doing it. *"It's nice… I've always wanted to be able to change the world in some way."* #### [15:19] Jakob's Law and convergence - **Jakob's Law**: users spend most of their time on *other* products, so they prefer yours to work like the ones they already know. - There's probably a better way to represent chat, but habit makes it nearly impossible to change without something truly groundbreaking. Categories converge: phones became **black rectangles**, and **all streaming apps look the same**. #### [15:49] Morphing the pattern: Figma and Uber - **Figma cursor chat**: the obvious move would be a chat sidebar. Instead, since the **cursor represents the person**, you type and the text appears **next to your cursor**. There's no send, no message list and no history. It's **proximity-based and ephemeral**: only people near your cursor see it, a digital version of speaking to the person next to you. - **Uber rider–driver chat**: drivers can't text while driving, so **rider messages are read aloud** and the driver can reply with **one tap, a thumbs-up**. **Delivered/read status** is kept, because riders mostly wanted to know: *"Did the driver read my message?"* ### [16:52] Outro - Teaser: the best products are secretly built like **games** (links to Enrico's video *The Weird Way Tech Steals From Games*). It closes with the signature *"…the next episode of Behind the Product."* ### Key takeaways - **Settings design changes behavior.** WhatsApp's reciprocal read-receipt toggle kept the feature alive. - **Input mechanics shape output.** The Enter key decides whether you get emails or texts. Toolbars and box height signal formality. - **Purpose shapes the chat.** Instagram optimizes sharing (sends per reach), while WhatsApp throttles it (forward limits). - **Slack is for the record; Discord is for the moment.** Look at threads, auto-archive and presence. - **The chat bubble is a 1997 Apple sketch** inspired by comics and MUDs. Live typing failed and left behind the typing indicator. - **Jakob's Law** explains convergence. Innovation happens by *morphing* the pattern (Figma cursor chat, Uber read-aloud). ## 2) Things mentioned ### Products and companies | Item | Role in the video | |---|---| | **WhatsApp** (Meta) | Blue-tick read receipts (2014), reciprocal hide toggle, forward limit of 5 chats, "forwarded many times" label and cap. | | **iMessage / Messages** (Apple) | Non-reciprocal read receipts, formatting options (bold/italic/underline/strikethrough), the bubble layout descended from iChat. | | **WeChat** (Tencent) | No read receipts by design (internal lecture). | | **Facebook Messenger** (Meta) | Thumbs-up in place of send when the box is empty, which fixed the "K" problem. Early reactions. | | **TechCrunch** | Covered the "K" phenomenon and Messenger's thumbs-up. | | **Slack** (Salesforce) | Enter-to-send A/B test and setting, persistent formatting toolbar, code-block Enter flip, threads with "Also send to channel," Active/Away auto-presence, searchable archive for agents. | | **Discord** | Inline replies, opt-in threads that auto-archive, four presence states including Invisible, game and Spotify activity status. | | **Spotify** | Listening activity shown on Discord. | | **Instagram** (Meta) | DMs as a Reels-sharing engine, paper-plane share sheet, "sends per reach" ranking signal, Messages moved to the nav bar. | | **Telegram**, **KakaoTalk** | Adopted the same bubble layout. | | **Twitch** | Chat as a garbled multi-user stream. | | **IRC**, **MUDs**, **Zork** | Pre-bubble chat and text-adventure lineage. | | **iChat** (Apple, Mac OS X 10.2 Jaguar, 2002) | First mainstream speech-balloon chat UI. Tried a live-typing preview, which became the typing indicator. | | **ClarisWorks** | Tool Alfke used for the 1997 sketch. | | **Microsoft Comic Chat** | Earlier literal comic-panel chat ("visual gimmick"). | | **AIM, ICQ** | IM clients of the era, referenced in Alfke's sketch notes. | | **iPhone SMS app** (2007) | Brought iChat bubbles to phones. | | **Google Docs** | Older in-document chat panel shown as B-roll. | | **Figma** | Cursor chat: proximity-based, ephemeral, attached to the cursor. | | **Uber** | Rider messages read aloud to drivers, thumbs-up one-tap reply, read status. | | **Granola** | Sponsor. AI meeting notes plus **Granola MCP** for Claude, Codex and other agents. | | **Claude** (Anthropic), **Codex** (OpenAI) | Agents that read Granola calls. Slack's archive as agent-readable memory. | | **Flask** (flask.do) | Enrico's video collaboration tool (in the description, and on his T-shirt in the sponsor segment). | | **Minecraft** | Redstone-build coordination as the Discord use case. | ### Design concepts and terms - **Read receipts** and **reciprocal privacy settings** (game theory of opt-outs). - **Acknowledgment shortcuts**: thumbs-up send button, **reactions**. - **Enter vs. Shift+Enter** send semantics and **context-sensitive key behavior** (code blocks). - **Affordances that signal formality**: persistent formatting toolbar, multi-line composer height. - **Share sheet / friend-face picker**, the **"sends per reach"** ranking signal, **navigation-bar placement** as a priority signal. - **Forwarding limits** and **"forwarded many times" labels** as anti-misinformation and anti-spam friction. - **Threads vs. inline replies**, **"Also send to channel"**, **thread auto-archive**, **searchability as a company record**. - **Presence design**: automatic Active/Away vs. user-chosen statuses, **Invisible** mode, **rich presence** (game/music activity), presence as surveillance. - **Speech-balloon chat UI**: left/right alignment, tails showing the speaker, per-speaker color. - **Typing indicator** (descended from the live-typing preview), the reported Apple patent. - **Jakob's Law** (Jakob Nielsen) and **design convergence**. - **Ephemeral, proximity-based chat** (Figma cursor chat), **voice-first, one-tap replies** for drivers (Uber). - **MCP (Model Context Protocol)**, AI agent **"harness"** of skills and instructions. ## 3) Biographies ### Enrico Tartarotti (host, co-writer) Italian-born tech creator and designer behind the YouTube channel **Enrico Tartarotti** (about 255K subscribers). His series ***Behind the Product*** goes behind the scenes of everyday tech products through designed video essays on UX and product design. He builds **Flask** (flask.do), a video collaboration and review tool, and runs **Rakugo Media** for sponsorships. Credits for this video: written by Enrico Tartarotti and **Andrej Andonov**, produced by Enrico and **Bartek Malinowski**, edited by **Seequence**. Find him on X as @EnriTarta and on Instagram as @enritarta. ### Jens Alfke (interviewee) Longtime software engineer who spent many years at **Apple**, where he worked on **iChat** and is credited with its **speech-balloon chat interface**. He sketched it in ClarisWorks in **April 1997**, inspired by comics, MUDs and IRC. He also worked on other Mac OS X networking and web features, including Bonjour/Rendezvous-era collaboration tech and Safari RSS. He later worked on sync and database software (Couchbase Mobile), and he blogs about software history. In the video he explains the comic-strip inspiration, the technical challenge of drawing bubbles behind text, and the failed live-typing preview that became the typing indicator. ### People referenced - **Adam Mosseri**: Head of Instagram (since 2018), quoted on **"sends per reach"** as one of Instagram's most important ranking signals. - **Marques Brownlee (MKBHD)**: tech YouTuber, shown complaining that swiping over in Instagram now opens Reels instead of the inbox. - **Steve Lemay**: Apple human-interface designer credited in Alfke's blog post with "Aqua-fying" the iChat speech balloons. - **Jakob Nielsen**: usability pioneer and co-founder of the Nielsen Norman Group, namesake of **Jakob's Law** ("users spend most of their time on other sites"). - **Andrej Andonov**: co-writer. **Bartek Malinowski**: co-producer. **Seequence**: editing studio. - The **WeChat internal lecture** speaker isn't named in the captions. (WeChat's creator **Allen Zhang** is known for annual internal and public talks on WeChat's design philosophy, including the decision not to add read receipts. This attribution is context.)