Shopify is moving from React Native back to Swift and Kotlin • Hacker News Board

Re: Shopify is moving from React Native back to Swift and Kotlin

#311

Post by tiborsaas » Thu, Sep 10, 2026, 5:15 PM UTC

_fzslm wrote: post #274

tonic_note wrote: post #243

Models have gotten a lot better at generating native iOS apps. The main appeal of RN was being able to leverage your web devs for mobile dev. that's what I did at my last company. And it's fine for a startup, but eventually you want dedicated native engineers bc each platform really deserves its own technical masters who can optimize for it. But now that all code is generated, there's little upside to having an RN ap…

This is true in a very real sense – models can help you build native apps very quickly, no question. But how do you keep them from drifting apart from one another as you add/change features or design? Right now, there isn't much tooling for this. React Native's advantage of having a single source of truth for code hasn't quite gone away yet, imo.

You create a source of truth which defines all the features and requirements. This can be UI tests, MD files, database, diagrams, whatever that fits your use case.

Re: Shopify is moving from React Native back to Swift and Kotlin

#312

Post by vmg12 » Thu, Sep 10, 2026, 5:16 PM UTC

muddi900 wrote: post #290

It is the "why use python" for mobile. The native apps will definitely be better in terms of performance and UX. However, having 2 codebases means twice the tokens.

The problem isn't tokens but verification that the code works.

Re: Shopify is moving from React Native back to Swift and Kotlin

#313

Post by keeda » Thu, Sep 10, 2026, 5:17 PM UTC

seanhly wrote: post #47

Bragging about "using agents to code pre-GPT" is quite the corporate flex... weren't they notoriously bad back then? Might as well say, "We've been doing spreadsheets with quantum computing since 2016"

I would not say they were bad, mostly just primitive compared to what we have today. I can only presume they are talking about GitHub Copilot which was released before ChatGPT. I believe at the time it was little more than “spicy autocomplete.” Yet it could be surprisingly capable, e.g. I recall this blog, also pre-ChatGPT: https://medium.com/data-science/github-copilot-crushes-data-...

That said I did happen to work with a team in ‘21 - ‘22 that got access to an older coding model from OpenAI, also called Codex, through a corporate partnership. We also tested it out in an autocomplete UX. Our experience was rather hit-or-miss and I was a bit skeptical of AI-based coding at the time. That blog post above and others like it were an eye-opener and made me wonder if we were just “holding it wrong.”

Then ChatGPT was released. It was nowhere as good as the models today but it could write reams and reams of correct code and I realized the world had changed forever.

Re: Shopify is moving from React Native back to Swift and Kotlin

#314

Post by dyauspitr » Thu, Sep 10, 2026, 5:20 PM UTC

dboreham wrote: post #309

dyauspitr wrote: post #238

Earlier quoted context omitted.

First “production is down” page means you just tell codex production is down and to fix it.

Presumably a sarcastic post, but this is actually going to be how things are done soon. I had a box that OOMed and needed to be rebooted every few weeks. It was a disaster recovery standby box so figuring out what was going on never rose to the top of my priority list. So I asked Claude to dig into it (proxying the commands it wanted to run through me) and in an hour it had diagnosed the problem, fixed it, and taught…

Not sarcastic. I have a moderately successful app and I haven’t once looked at the code (though I am capable, so far atleast). The only time I open Xcode is if I have to modify signing certificates. I did set up a slack workflow with a “fix it” button that basically tells Codex to fix the issue, run comprehensive tests, manually UI test for that particular issue with computer use and then deploy it.

Re: Shopify is moving from React Native back to Swift and Kotlin

#315

Post by Dfiesl » Thu, Sep 10, 2026, 5:21 PM UTC

professoretc wrote: post #293

Dfiesl wrote: post #279

Earlier quoted context omitted.

Android and iphone emulator MCP, model compares screens, flags is theres drift? Something like that I’d guess

But the screens should look different, right? That's the point of building separate iOS vs. Android versions is to make each version "native" to its platform. The feature-set should be the same, but the interfaces can diverge.

I think the whole native thing is more for better performance, debugging ease and dependency reduction rather than seeking variation in UIs.

Re: Shopify is moving from React Native back to Swift and Kotlin

#316

Post by pessimizer » Thu, Sep 10, 2026, 5:21 PM UTC

wredcoll wrote: post #239

shiflett wrote: post #135

Earlier quoted context omitted.

I think they were speaking as a user. These tools create inferior products. (Still not technically objective, but true nonetheless.) That doesn't mean companies should necessarily avoid them. As a user, I always want the best possible user experience, but a company can't prioritize that above all else, and I know that.

I am so tired of existing react/electron applications being compared against imaginary, hypothetical "native" applications. Like, it's fine to criticize something, "this component doesn't follow the OS's UI guidelines" or "this scrollbar disappears when the mouse isn't over it which is a bad UX" or whatever, but this generic "oh this is bad but if it was rewritten it would be perfect" is annoying.

It's always the preference of people defending bad decisions to compare them to doing nothing.

What you're seeing is people actually making that case instead of forcing it. They're saying that if the app wouldn't exist without this bad thing, then it is appropriate to compare using the bad thing to doing nothing.

You just seem to be demanding that people not mention other ways to do things, or you'll get angry.

Re: Shopify is moving from React Native back to Swift and Kotlin

#317

Post by zelphirkalt » Thu, Sep 10, 2026, 5:22 PM UTC

polloRebozado wrote: post #202

I have not coded any mobile apps, I understand the downsides of using react native/electron due to them being web apps but what about things like Kotlin multi platform or flutter? Aren't this frameworks supposed to allow your to have 1 codebase and the apps be truly native instead of web apps?

I think any framework that aims to support desktop and mobile frome the same code per view/screen is doomed to either make one of those two awkward to use, or alternatively become itself very complex to use.

The most advanced in this area may well be websites and into those decades of work of thousands of engineers went (HTML, CSS and JS standards).

Re: Shopify is moving from React Native back to Swift and Kotlin

#318

Post by replygirl » Thu, Sep 10, 2026, 5:22 PM UTC

_fzslm wrote: post #274

tonic_note wrote: post #243

Models have gotten a lot better at generating native iOS apps. The main appeal of RN was being able to leverage your web devs for mobile dev. that's what I did at my last company. And it's fine for a startup, but eventually you want dedicated native engineers bc each platform really deserves its own technical masters who can optimize for it. But now that all code is generated, there's little upside to having an RN ap…

This is true in a very real sense – models can help you build native apps very quickly, no question. But how do you keep them from drifting apart from one another as you add/change features or design? Right now, there isn't much tooling for this. React Native's advantage of having a single source of truth for code hasn't quite gone away yet, imo.

the problem is that single-source advantage gradually falls away as you develop your software into something that feels good to use on each platform. and once you have a quality product you're left with perfunctory coupling that makes it harder to adopt the latest platform features

Re: Shopify is moving from React Native back to Swift and Kotlin

#319

Post by chasd00 » Thu, Sep 10, 2026, 5:23 PM UTC

nemomarx wrote: post #214

suriyaG wrote: post #129

Earlier quoted context omitted.

not sure why you're getting downvoted. but if you're building even very popular applications, it is quite easy to see how LLMs are very well suited for this type of consistency job. - they follow instructions quite well. - are tireless at doing mechanical ports between languages and frameworks. - Can understand a new ecosystem quite well.

Then why aren't people doing that? Microsoft has as much access to cheap tokens as any software company around, right, so you'd think they would be leading the way.

they probably are but have some patience.

Keep in mind, claudecode and the other coding agents were pretty bad until around Jan of this year (2026). So it's only been about 9 months since devs have had decent coding agents and even less time has elapsed since somewhat wide adoption.

Re: Shopify is moving from React Native back to Swift and Kotlin

#320

Post by raspo » Thu, Sep 10, 2026, 5:24 PM UTC

jrochkind1 wrote: post #268

I'm not totally following the part about the simulator(s), probably because I haven't actually done mobile development before. > When simulator interaction is needed, the CLI can connect to them via a remote mode and drive the UI via commands without having to inspect the layout or the accessibility tree. This enables blazing-fast performance and E2E tests. I think I'm not following. Don't you still need to test the…

I have done some iOS development and still couldn't follow what the article was saying about the simulator. I'm actually quite interested in it, because (in my experience at least) verifying that the UI works as expected is quite painful with current LLMs and the developer tools available. They talk about building a CLI and keeping business logic isolated, ok fine, but do they still run the simulator and take screenshots to verify their work?!