I've been around long enough to see this argument come and go under a lot of different names. This time it's AI. Maybe AI really does change the economics. But this post doesn't demonstrate it.

Talk to me in a year.

The side-by-side comparisons? Whoopty do. It's different code. Of course agents can produce two implementations that look the same today. That's not the hard part.

The hard part is keeping them the same.

Feature parity isn't an implementation cost. It's a divergence cost. It accrues over years across experiments, analytics, accessibility, edge cases, bug fixes, platform behavior, and a thousand little decisions which current agents aren't great at tracking.

Agents can write code fast but they aren't a panacea.

The load-bearing sentence in the whole post is this:

"Shared specifications, tests, and review checkpoints dramatically reduced the cost of maintaining parity."

Okay. For how long? By how much? Got any numbers to share? How will these hold up under contact with customer?

You haven't maintained parity yet. You've built prototypes. You're making a claim about a cost that compounds over time based on what it costs at t=0.

The other thing missing is the counterfactual. They keep comparing this rewrite to what a rewrite would have cost before coding agents. But what if you point those same agents at the existing RN codebase?

If agents make software development cheaper, they make RN development cheaper too. And now you're modifying one implementation instead of generating, testing, reviewing, and reconciling two.

The tooling section makes this even stranger. They find that agents are bad at driving simulators, so they pull business logic out of the UI, make it runnable headlessly, and expose a CLI.

That's a good idea! Do that!

But that's an architecture change, not an argument for native. You can make an RN codebase agent-friendly without rewriting five apps.

Then you get to "Preventing slop," which is probably the most important section in the post. Just pointing an LLM at the codebase doesn't work. They had to build Helix, with ordered checkpoints, test proofs, visual diffing, adversarial reviewers, and human gates.

So what they've actually demonstrated is that Shopify has enough engineering resources and agent infrastructure to make maintaining two codebases look economically plausible.

Maybe it is! For Shopify.

That's a much narrower claim than "AI changes the economics of cross-platform development."

And where are the numbers?

For a post about reevaluating costs from first principles, there's remarkably little cost data. Engineer hours? Review time? Defect rates? Parity failures? Agent spend? Ongoing maintenance? Anything?

They even say RN performance isn't the problem. "React Native apps can be fast. Ours are."

So there's no product crisis here. No performance crisis. There's an internal cost argument, with no numbers, being used to justify rewriting five apps used by millions of merchants.

And in isolation I'd probably just shrug and say: Shopify made a bet. Let's see how it goes.

But it's harder to view it entirely in isolation when they brought Tailwind on yesterday too.

Shopify used to be one of the great stewards of the broader ecosystem. What worries me about the recent direction isn't any single technology choice. It's the appearance that, following the recent tech leadership changes, we're starting to see decisions driven more by the preferences of the people now making them than by demonstrated technical merit.

Maybe that's an unfair read. I hope it is. But posts like this don't help, because if you're going to make a sweeping technical argument for a major change, show the evidence.

The part I actually find convincing is much less exciting: Shopify is tired of paying the upstream tax. They've spent years working on RN performance, improving the framework, dealing with dependencies and upgrades, etc.

Fair enough. That's a real cost. Being an RN framework developer or dependent is -- or has been -- awful -- it's like trying to fly a kite in a hurricane. The web team has been super disciplined and also ridiculously slow. The RN team changes apis in .. questionable ways with regards to compatibility

But it's not new, and it has very little to do with LLMs.

And let's not get me started on taking this kind of dependency for your business on companies who still don't have any idea how much to charge for their tools and are all operating (on a per token basis) at a loss. They're swapping some framework dependency for dependency on coding models whose capability, pricing, and terms they don't control.

None of this means they're making the wrong decision. Maybe they're right. Maybe in three years this looks obvious.

But that's exactly the point.

Come back in a year and show me parity bugs, engineering hours per feature, experiment drift, accessibility regressions, review burden, model spend, and how much human work it takes to keep the implementations aligned.

Right now they've shown that AI makes rewrites cheaper.

Whoopty do.

Shopify is moving from React Native back to Swift and Kotlin