Every codebase grows a shared/ folder, and given enough time every shared/ folder becomes a junk drawer. Not because the team got lazy — because the folder was never given a rule. Here's why it rots, and how to keep it boring.
The idea that React could render a 3D scene sounds like a stretch — React is for interfaces, 3D is a different universe. Except it isn't a stretch at all, and understanding why closes out this whole series with its central idea: React was never really about the DOM. This is where that finally becomes obvious.
React Native's promise gets misremembered as 'write once, run everywhere' — and that misremembering is why so many web developers hit a wall. The knowledge transfers; the code and the instincts often don't. Here's the honest line between what your React experience buys you on mobile and what it quietly doesn't.
The pitch is irresistible — ship your React app as a real desktop program, same code, native icon in the dock. Electron and Tauri both promise it. But the interesting question isn't 'can I,' it's 'what do I actually gain that a browser tab can't give me,' and the answer decides which tool, and whether you should bother at all.
Every team writes component docs the same way — a wiki page, a screenshot, a table of props — and every team watches them go stale within a month. The problem isn't discipline. It's that the docs live in a different place than the code. The fix is docs that can't drift because they're generated from the component itself.
Most engineers treat the Figma file as a picture to reproduce. That framing is why so many handoffs go badly. A good design isn't a picture — it's the first draft of your component architecture, and the decisions that decide whether your codebase stays sane are made before a single line of React is written.
"Just send them an email" is one of those sentences that sounds like a five-minute task and turns into a week. The React part is trivial. The hard part is that email is a deceptively deep backend system with deliverability, templates, and reputation — and none of it belongs in your frontend. Here's where the real work actually is.
An upload looks like a one-liner — a file input, a POST, done. Then someone uploads a two-gigabyte video on hotel wifi and the whole illusion collapses. The hard part was never the input. It's moving a large, unreliable blob of bytes from a browser to somewhere it can live. Here's how I actually handle it.
Dates look like the most boring data type in your app. They are also the source of the subtlest, most embarrassing bugs — the meeting that shows an hour off, the 'today' that's tomorrow in Tokyo, the date that shifts a day every time you save it. Here's how I stop time from quietly breaking a React app.
Taking a payment looks like a form submission and is nothing like one. The card number is radioactive, the confirmation is asynchronous, and the one thing your React app must never do is believe it got paid because a callback said so. Here's where the real line sits between the browser, your server, and Stripe.