irskep a day ago

I agree with most of the other comments here, and it sounds like Shopify made sound tradeoffs for their business. I'm sure the people who use Shopify's apps are able to accomplish the tasks they need to.

But as a user of computers and occasional native mobile app developer, hearing "<500ms screen load times" stated as a win is very disappointing. Having your app burn battery for half a second doing absolutely nothing is bad UX. That kind of latency does have a meaningful effect on productivity for a heavy user.

Besides that, having done a serious evaluation of whether to migrate a pair of native apps supported by multi-person engineering teams to RN, I think this is a very level-headed take on how to make such a migration work in practice. If you're going to take this path, this is the way to do it. I just hope that people choose targets closer to 100ms.

  • fxtentacle a day ago

    I would read the <500ms screen loads as follows:

    When the user clicks a button, we start a server round-trip and fetch the data and do client-side parsing, layout, formatting and rendering and then less than 500ms later, the user can see the result on his/her screen.

    With a worst-case ping of 200ms for a round-trip, that leaves about 200ms for DB queries and then 100ms for the GUI rendering, which is roughly what you'd expect.

    • joaohaas a day ago

      Since the post is about the benefits of react, I'm sure if requests were involved they would mention it.

      Also, even if it was involved, 200ms for round-trip and DB queries is complete bonkers. Most round-trips don't take more than 100ms, and if you're taking 200ms for a DB query on an app with millions of users, you're screwed. Most queries should take max 20-30ms, with some outliers in places where optimization is hard taking up to 80ms.

      • bobnamob 20 hours ago

        > 200ms for round-trip and DB queries is complete bonkers

        Never lived in Australia I see

      • xmprt a day ago

        > Most queries should take max 20-30ms

        Most queries are 20-30ms. But a worst case of 200ms for large payloads or edge cases or just general degradations isn't crazy. Without knowing if 500ms is a p50 or p99 it's kind of a meaningless metric but assuming it's a p99, I think it's not as bad as the original commenter stated.

      • fxtentacle 14 hours ago

        I have a 160ms ping to news.ycombinator.com. Loading your comment took 1.427s of wall clock time. <s>Clearly, HN is so bad, it's complete bonkers ;)</s>

        time curl -o tmp.del "https://news.ycombinator.com/item?id=42730748"

        real 0m1.427s

        "if you're taking 200ms for a DB query on an app with millions of users, you're screwed"

        My calculation was 200ms for the DB queries and the time it takes your server-side framework ORM system to parse the results and transform it into JSON. But even in general, I disagree. For high-throughput systems it typically makes sense to make the servers stateless (which adds additional DB queries) in exchange for the ability to just start 20 servers in parallel. And especially for PostgreSql index scans where all the IO is cached in RAM anyway, single-core CPU performance quickly becomes a bottleneck. But a 100+ core EPYC machine can still reach 1000+ TPS for index scans that take 100ms each. And, BTW, the basic Shopify plan only allows 1 visitor per 17 seconds to your shop. That means a single EPYC server could still host 17,000 customers on the basic plan even if each visit causes 100ms of DB queries.

      • andy_ppp a day ago

        I do not understand this thinking at all, a parsed response into whatever rendering engine, even if extremely fast is going to be a large percentage of this 500ms page load. Diminishing it with magical thinking about pure database queries under load with no understanding of the complexity of Shopify is quite frankly ridiculous, next up you’ll be telling everyone to roll there own file sharing with rsync or something…

    • fidotron a day ago

      If you are good those numbers are an order of magnitude off. In truth it is probably mostly auth or something. If you simply avoid json you can radically attack these things fast.

      RTT to nearest major metro DC should be up to 20ms (where I am it is less than half that), your DB calls should not be anything like 200ms (and in the event they are you need to show something else first), and 10-20ms is what you should assume for rendering budget of something very big. 60hz means 16ms per frame after all.

      • gf000 a day ago

        What percentile? Topics like these don't talk about the 5G connected iphone 16 pro max, but have to include low-end phones with old OS versions and bad connectivity (e.g. try the same network connectivity in the London metro, where often there is no receiption whatsoever).

        As you reach for higher percentiles, RTT and such start growing very fast.

        Edit: other commenter mentioned 75% as percentile.

      • x0x0 a day ago

        > RTT to nearest major metro DC should be up to 20ms (where I am it is less than half that)

        over a mobile network? My best rtt to azure or aws over tmobile or verizon is 113ms vs 13ms over my fiber conection.

    • sgarland a day ago

      > 200ms for DB queries

      No. Just no. There’s an entire generation of devs at this point who are convinced that a DB is something you throw JSON into, use UUIDs for everything, add indices when things are slower than you expected, and then upsize the DB when that doesn’t fix it.

      RAM access on modern hardware has a latency of something like 10 nanoseconds. NVMe reads vary based on queue depth and block size, but sub-msec is easily attainable. Even if your disks are actually a SAN, you should still see 1-2 msec. The rest is up to the DB.

      All that to say, a small point query on a well-designed schema should easily execute in sub-msec times if the pages are in the DB’s buffer pool. Even one with a small number of joins shouldn’t take more than 1-2 msec. If this is not the case for you, your schema, query, or DB parameters are sub-optimal, or you’re doing some kind of large aggregation query.

      I took a query from 70 to 40 msec today just by rewriting it. Zero additional indexing or tuning, just unrolling several unnecessary nested subqueries, and adding a more selective predicate. I have no doubt that it could get into the single digits if better indexing was applied.

      I beg of devs, please take the time to learn SQL, to read EXPLAIN plans, and to measure performance. Don’t accept 200 msec queries as “good enough” because you’re meeting your SLOs. They can be so much faster.

      • charleslmunger a day ago

        >RAM access on modern hardware has a latency of something like 10 nanoseconds

        What modern hardware are you using that this is true? That's faster than L3 cache on many processors.

        • sgarland 14 hours ago

          Correction: DRAM latency is ~10 - 20 nsec on most DDR4 and DDR5 sticks. The access time as seen by a running program is much more than that.

          As an actual example of RAM latency, DDR4-3200 with CL22 would be (22 cycles * 2E9 nsec/sec / 3200E6 cycles/sec) == 13.75 nsec.

      • ezekiel68 18 hours ago

        Beg all you want. They're still going to dump JSON strings (not even jsonb) and UUIDs in them anyway, because, "Move fast and break things."

        I lament along with you.

        • sgarland 14 hours ago

          “We’re disrupting!”

          “Yeah, you’re disrupting my sleep by breaking the DB.”

      • fxtentacle 13 hours ago

        "All that to say, a small point query on a well-designed schema should easily execute in sub-msec times if the pages are in the DB’s buffer pool"

        Shopify is hosting a large number of webshops with billions of product descriptions, but each store only has a low visitor count. So we are talking about a very large and, hence, uncacheable dataset with sparse access. That means almost every DB query to fetch a product description will hit the disk. I'd even assume a RAID of spinning HDDs for price reasons.

        • sgarland 13 hours ago

          Shopify runs a heavily sharded MySQL backend. Their Shop app uses Vitess; last I knew the main Shopify backend wasn’t on Vitess (still sharded, just in-house), but I could be wrong.

          I would be very surprised if “almost every query” was hitting disk, and I’d be even more surprised to learn that they used spinners.

      • refset 14 hours ago

        > just unrolling several unnecessary nested subqueries, and adding a more selective predicate

        And state of the art query optimizers can even do all this automatically!

      • reissbaker a day ago

        I think 500ms P75 is good for an app that hits network in a hot path (mobile networks are no joke), but I agree that 200ms is very very bad for hitting the DB on the backend. I've managed apps with tables in the many, many billions of rows in MySQL and would typically expect single digit millisecond responses. If you use EXPLAIN you can quickly learn to index appropriately and adjust queries when necessary.

        • gooosle a day ago

          500ms p75 is not good for the (low) complexity of the shopify app.

          Also reporting p75 latency instead of p99+ just screams to me that their p99 is embarrassing and they chose p75 to make it seem reasonable.

    • cellularmitosis a day ago

      100ms to render an iOS screen means dropping 6 frames. That would put an applicant in the "no hire" category.

    • gooosle a day ago

      The 500ms number is p75 - not worst case at all.

      200ms round trip is like 10x more than what's reasonably possible.

      Same with your other numbers.

    • bluGill a day ago

      People have gotten used to that, but UI work back to the 1960s has done studies and showed clearly that for many of these operations you get tens of ms before people notice and their attention wanes. The web often doesn't allow for response times as fast as the humans need, which is a good reason to write real apps not web apps. That is also why I use tabs - load a bunch in the background so when I'm ready I can just switch tabs and it is there.

    • np_tedious a day ago

      What does "DB queries" mean here? The on-device sqlite stuff?

  • lelandfe a day ago

    500ms is the 75th percentile speed, so 75% of users are having load times faster than that. For context, Google's synthetic p75 loads emulate a crappy old Android phone on a bad network.

    A linked post[0] says their p75 was 1400ms before 2023, yowza.

    [0] https://shopify.engineering/improving-shopify-app-s-performa...

    • yxhuvud 19 hours ago

      > so 75% of users are having load times faster

      No. It on a request basis, meaning that one in a four clicks a user does take more than half a second to complete. Slow times for as low percentiles as 75 mean users hit the bad cases very often in practice.

      • [removed] 14 hours ago
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    • [removed] a day ago
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    • pinoy420 a day ago

      2 seconds to wait for a webpage to load isn’t even that bad. If you take an average user on facebook it is horrendously slow - to someone who knows how fast something can be - but no typical user cares/notices. They just accept it.

      Nike’s website is phenomenally quick. But again. Ask anyone if that is what they care about. Nope. It’s the shoes.

      • itishappy a day ago

        Then there's McMaster Carr, which has great service, but all anyone seems to want to talk about is how snappy their site is!

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  • afavour a day ago

    > Having your app burn battery for half a second doing absolutely nothing is bad UX. That kind of latency does have a meaningful effect on productivity for a heavy user.

    The implication is that React Native is to blame for this and I'm not sure that's true. What would the ms delay be with pure native? I have plenty of native apps that also have delays from time to time.

    • irskep a day ago

      It all depends on whether the number includes network roundtrip or not, which they don't state. I read it as not including a network request, i.e. all CPU and local I/O.

      • lolinder a day ago

        The article they link to about how they optimized talks about caching network calls as part of their strategy to get below 500ms, so I would assume network calls are included in the number.

  • irskep a day ago

    Replying to myself for clarification: I did not read their 500ms number as including waiting for a network. It sounded like that's how long it was taking React Native to load local data and draw the screen. If that's not the case, it's a very different story.

    From another comment by seemack (https://news.ycombinator.com/item?id=42730348):

    > For example, I just recorded myself tapping on a product in the Product list screen and the delay between the pressed state appearing and the first frame of the screen transition animation is more than half a second. The animation itself then takes 300ms which is a generally accepted timeframe for screen animations. But that half second where I'm waiting for the app to respond after I've tapped a given element is painful.

    • mustafa01ali 12 hours ago

      author here - the stated screen load time includes server round-trip, parsing, layout, formatting, and rendering.

      • irskep 9 hours ago

        In that case, I apologize for misunderstanding, and would edit my original comment if I could.

    • [removed] a day ago
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  • pjc50 14 hours ago

    Indeed. The games industry uses immediate mode GUIs and people get upset if they achieve less than 60fps. Having everything be this slow is just a huge failure of coordination on behalf of the industry.

    (next mini question: why is it seemingly impossible to make an Android app smaller than 60mb? I'm sure it is possible, but almost all the ones I have from the app store are that size)

    • tarentel 11 hours ago

      Can't speak for every app but I've worked on several through the years, a sizeable chunk of all the apps I've worked on were assets. It's possible to hide a lot of it from the app store size if you really wanted to but you'd end up downloading all the assets at some point anyway so there's really no point in putting the extra engineering effort in just to make your app store number look smaller.

      This obviously isn't the case for every app and most of the ones I've worked on had a lot of bloat/crap in them as well.

  • epolanski a day ago

    Make a single example of an app that from when I click to the opening takes less than that.

    I've just tried whatsapp, notes, gallery, settings and discord out of curiosity, none did and I have a very fast phone.

    • irskep a day ago

      It sounds like you're referring to app-launch time, which is different from screen-load time. Very different things!

  • SeptiumMMX a day ago

    Check out Avalonia [0]

    It's a cross-platform spiritual successor of WPF and it kicks ass! You get proper separation of models and views, you can separate what controls there are from how they look (themes/styles), you can build the entire thing into a native compiled application with very reasonable speed and memory use.

    [0] https://avaloniaui.net

  • jeswin 20 hours ago

    > I just hope that people choose targets closer to 100ms.

    Why? If it's about the phone burning battery for 500ms, it probably isn't doing that - it's just waiting for data to arrive. And even when it's rendering, it's probably not burning battery like say Uber (with which you can feel the battery melt in your hands).

    But that's not why I am commenting. I am writing because so many commentors are saying that 500ms is bad. Why is 500ms bad, as long as the UI is not freezing or blanking out?

    Why not lower expectations, and wait for half a second? Of course, there are apps for which 500ms is unacceptable - but this doesn't seem to be one of them.

  • brokencode a day ago

    Subjectively, I find the Shop app to be quite nice and speedy. It works well enough that I’d never have guessed it is using any kind of cross platform framework.

    It’s easy to get caught up on numbers, but at the end of the day the user experience is all that matters. And I very much doubt that performance is a concern for their users.

    • mirzap 19 hours ago

      Exactly. Tech people almost always go to the "performance wormhole" arguing about ms and how it could be improved 10x - myself included. But working at a startup the past couple of years, I came to the conclusion that it does not matter to the end users at all. If an app is "nice" and "speedy" as you say, that’s enough. Shopify made a good decision and tradeoffs; it works for them, and I would argue it would work for 90% of other companies as well. You don't really need a native app for most purposes; React Native and Flutter are good enough.

  • freedomben a day ago

    Assuming the 500ms is mostly delay for fetching data over a socket, unless the code is really broken that should not really be burning battery. <500ms for display of non-trivial network-fetched data is great regardless of whether it's rendered by react native or is a fully native app. They would both be I/O-bound on the network primarily, with a small but insignificant compute overhead for RN. If the data needs lots of transformation (though not compute-intensive transformation like calculating hashes or somethign) upon returning that could make a difference, though again I'd be surprised if CPU for RN vs native was all that different.

    As an Elixir dev who aims for and routinely achieves <10ms response times, (and sometimes < 1 ms for frequent endpoints that I can hand optimize into a single efficient SQL query, which Ecto makes easy I might add!) I find the response time to be the more egregious part :-D

  • x0x0 a day ago

    > Having your app burn battery for half a second doing absolutely nothing is bad UX.

    Why are you assuming the app is either burning much battery or even doing more than waiting on current data from the server? For an app that I would assume isn't much use without up-to-date data from the server?

nadis a day ago

I thought the section on the importance of native devs and how they're staffing mobile was really interesting:

"Native devs are crucial

Mobile engineers who specialize in iOS and Android are essential to building great mobile apps. There is no replacing experience and taste that comes from having built many mobile products and deeply understanding conventions and usability. Being able to drop down to the platform layer, write bindings, master build & release, distribution, etc requires native expertise.

They also play a vital role in optimizing app performance across the myriad of device models, ensuring a consistent user experience for all users. Additionally, native expertise is essential for managing React Native version updates, as well as adopting new features, APIs, and tooling changes that accompany new iOS and Android releases. You can't build a good product without these experts.

We invested in training our native mobile developers in React Native through a self-serve course that covered everything they needed to know to ship production-ready code. Additionally, we set up office hours with developers who were already proficient in React Native to provide support through Q&A sessions, pair programming, and code reviews.

We also supplemented our mobile teams with some web developers for their Javascript, Typescript, and React expertise. This ensured we had strong expertise in both native and React Native, and over time, it levelled up the entire team.

Having a good mix of native and web developers is the key to building great mobile apps using React Native in our experience. "

  • sdflhasjd a day ago

    Probably the first "we adopted x" blog post that I can find relatable and spot-on.

    I think it's one of the big misconceptions that React Native is _the_ path to get your web devs or even existing code onto mobiles. That's how you get the criticism that RN builds bad, mouldy apps.

    Between our clients that have had this issue with quality and shops in the same space as us that haven't (one who boasts a review on one of their apps being "an example on how to build a proper fully native app"), having a good portion of native devs on the team is a big differentiator. Unfortunately this means a RN Team isn't as cheap as some hope.

  • DanielHB 12 hours ago

    As someone who works with React Native this is definitely true. Imagine a venn diagram:

    Full Navive: 2 very big bubbles

    React Native: 2 small bubbles and one big bubble

    It doesn't happen very often but it can be quite annoying to implement features that need native controls on both platforms. In my case I only know native android (no ios) so when implementing native things I need to bring in an ios native dev and agree on the communication API and any platform-specific edge case before implementing stuff.

    It is a lot easier when I can do it all by myself and it is even harder for team members who have no native experience at all.

seemack a day ago

Blazing fast is a bold claim. I use this app nearly every day on a brand new Pixel 9 Pro and, while much improved from a few years ago, it is far from "blazing fast".

For example, I just recorded myself tapping on a product in the Product list screen and the delay between the pressed state appearing and the first frame of the screen transition animation is more than half a second. The animation itself then takes 300ms which is a generally accepted timeframe for screen animations. But that half second where I'm waiting for the app to respond after I've tapped a given element is painful. UX studies indicate 0.1s as a number where an application no longer feels instantaneous. (https://www.nngroup.com/articles/response-times-3-important-...)

Contrast this against something like the Slack app where the screen is navigating even before the pressed animation has appeared. Or for an app with probably not as much engineering focus, Fastmail, which begins the screen transition within 100ms of the pressed animation state appearance.

  • no_wizard a day ago

    I wonder a little bit why this is slower on Android than iOS. On iOS I've never experienced this, and my phone is a couple years old now.

    Not saying I have the answer, but it is a curiosity

    • seemack a day ago

      It's a good question! I've been hearing the joke for years that RN architects don't have any android devices to test on.

      • qt31415926 a day ago

        On our apps we consistently see a p50 3-4x speed difference between iOS and Android (though there are more lower end android devices). Hard to fathom if it's all due to variability in android devices vs RN being less performant on Android.

    • ge96 a day ago

      Developing for Apple can be a PITA with their strict background processing rules, apps just terminate/stop working unless they fall under a special case. I get it but yeah.

      edit: by terminate I don't mean crash, it just stops code execution an example is an active socket connection getting disconnected unless it's doing something like streaming audio

      • bschwindHN a day ago

        But as a user I appreciate the strictness much more. I don't have to worry about closing background apps or having a bunch of crap running when I'm not actively using it. The OS (mostly) handles that for me, as it should.

        • cosmic_cheese a day ago

          Absolutely. I’d rather have backgrounded apps unexpectedly closed from time to time than to find a big chunk of battery gone at a bad time because some app I don’t even care about has decided it needs to keep running and eating resources for some reason.

prophesi a day ago

I'm surprised that there was no mention of Expo. In the past, I would say bare-metal is better than Expo-managed React Native projects because of the limitations when it came to native modules. Fast forward to today, and anything you can do in a bare metal RN app can be done with Expo.

The biggest game-changer recently is Expo's Continuous Native Generation[0]. You can configure all of your native modules and ios/android files with a simple config file (which has its limits, whereby you'll need to write an Expo Config Plugin[1]). You will no longer commit the ios/android native code to your repository, and instead let it be procedurally built.

This resolved a lot of environment issues developers would often run into, and greatly simplified onboarding new devs. You can build your iOS/Android apps through the CI with ease. And you'll no longer be afraid of upgrading React Native, as Expo will handle all of the breaking changes in the native code for you.

My guess is that Shopify started with bare metal React Native apps (which I would have done the same 5 years ago), and now migrating back to Expo-managed projects is nontrivial. At my work we only manage one app, and it was well worth migrating back.

[0] https://docs.expo.dev/workflow/continuous-native-generation/

[1] https://docs.expo.dev/config-plugins/introduction/

  • gunian a day ago

    What are your thoughts on Flutter vs Expo vs React Native for someone that wants to build a native app for fun?

    • deergomoo 16 hours ago

      React Native renders actual native widgets to the screen, so for example on iOS you would write to cross-platform abstractions but you’d still get real UIKit components on the screen.

      Flutter draws its own components that can look superficially like the target platform (or not, it’s up to the developer) in a manner closer to a game engine. HN seems to love Flutter and apparently the developer experience is excellent, but as a user I find Flutter apps to be in general a poor experience. They rarely look or act quite right (assuming the developers even try; I’ve used a number that look like someone has transplanted an Android app onto iOS).

      • gunian an hour ago

        This is fascinating how does Flutter try to make up for the performace hit that comes with adding a layer of abstraction?

    • sdflhasjd 13 hours ago

      My thought is that Expo prioritises web compatibility too much to the point that it leans into conventions with things like navigation that are web-oriented and these contribute towards an app not feeling like a native app.

    • reddalo a day ago

      > Expo vs React Native

      Expo is React Native with some nice things sprinkled on top. I'd go with Expo.

      • gunian 19 hours ago

        why Expo over Flutter? do React Native and Expo provide better abstractions over the Java/ObjC native APIs? again I've never done native dev just curious sorry if this isnt HN worthy comment

    • EddieRingle a day ago

      None of those will get you a "native" app, but they might get you most of the way to a cross-platform app.

      • gunian a day ago

        fair point but coin toss it is what I'm getting they are all equally good/bad?

zffr a day ago

> Our apps are blazing fast (<500ms screen loads)

I’m not sure I would consider 0.5 seconds to be blazing fast.

I wish the article went into detail on what these screens do and what a screen load means exactly.

  • canucker2016 a day ago

    You'd hope they benchmarked the old native iOS app and the RN app.

    Since the blog post doesn't mention previous native-only perf, I'd assume they didn't compare or the RN version isn't close to native-only perf (leaning heavily towards the second reason).

    Looking at a previous blog post, the first hunch seems to be correct - the second may also be true.

    From 2024 March, https://shopify.engineering/improving-shopify-app-s-performa... talks about how their RN-ified app was loading screens in 1400ms (P75) and the steps they took to reduce that to 500ms.

    I hope they benchmark their load-screen time with every release/CD to stay on top of any regressions, otherwise, there'll be more mad scrambles when the perf debt piles up too high.

  • hombre_fatal a day ago

    Right after that, they have three links (one blog post, two videos) to explanations of how they optimized screen load speed that can answer that question.

    It's a mix of layout stuff (like using lazy list views to avoid below the fold rendering) and network fetches (they talk about using better caching).

  • buzzerbetrayed a day ago

    That was my initial thought as well. Anyone know what native screen loads typically are? I’m sure it varies wildly between apps, but 500ms seems like it would be on the slower end of a “fast” app.

    • zffr a day ago

      It really depends on what a "screen load" means exactly. If its just rendering the screen from some client-side data then I would expect something <16ms. To support 120fps displays, it would need to be <8ms.

      If a "screen load" includes making a network request to fetch data, then this is a very weird metric to include in a post about React Native. Most of that time budget should just be waiting for the request to complete. Just as before, it should take <16ms to render the screen once the data arrives.

    • kllrnohj a day ago

      > Anyone know what native screen loads typically are?

      500ms sounds about right for a cold launch but otherwise is pretty poor.

      50-100ms for "minor" screen changes and 100-200ms for "major" ones are otherwise reasonable for native screens.

    • cellularmitosis a day ago

      For typical apps, the four variables here are backend latency, network latency, client-side deserialization, and client GUI rendering. (Less commonly, apps which have complex client-side state will also spend time reconciling server and client state.)

      Keeping UI rendering under 16ms is the gold standard for native apps. That leaves only deserialization as the other target which the mobile developer can optimize. However, the typical solution there involves convincing the backend to ship a different format (i.e. switching from JSON to binary PList or to SQLite DB file).

      • kllrnohj a day ago

        > Keeping UI rendering under 16ms is the gold standard for native apps.

        No, it isn't.

        If you're not including the actual rendering, so the actual code of the app only or at least only the code on the UI thread, the targets are much smaller. More like 3-6ms/frame.

        If you're including rendering then pipelining and 90hz+ being common still changes that anyway.

      • wiseowise 19 hours ago

        > Keeping UI rendering under 16ms is the gold standard for native apps.

        Not since they’ve started releasing 120hz screens.

    • lawgimenez a day ago

      For reference, our app is 100% in Jetpack Compose, our screen rendering for both cold and warm are in the average of ~460-480ms. App start is around ~480ms.

      • charleslmunger a day ago

        If your warm and cold starts are that close I'take a closer look at your measurement methodology. Could be your cold starts are actually warm, or your timing is starting late.

fidotron a day ago

This strikes me as curiously defensive, in that Canadian way of praising things that are obviously problematic to draw attention to them.

The wider noise around React Native is seemingly that it works, especially while iterating on things, but it makes the final 20% of work much harder than it already was. As one person put it to me recently “with RN you just have to face the fact you won’t be winning any design awards”.

What really amazes me is how far React Native and web React have separated, to the point using the web one is a complete non event.

  • bloomingkales a day ago

    I just kinda looked around the Shopify app to get a feel for it. There are a few frameworks that tap into native view switching (transitioning between pages and tabs), which creates most of the native feeling (along with native view components like lists/menus/switches).

    I don’t know why the quality of the app feels cheap, but it just feels so (the web views load in with zero ease, they just jank onto the screen. So while you have native screen transitioning, you still have this low quality feeling of a bad nypost article shitting out an ad popup on you. Hard to explain, but that’s my my general feeling).

    Regardless, while not impressive, it’s in this non-impressiveness that informs my unwillingness to invest into native or something like Flutter. These apps are too simple to go through the hoops.

    Shopify RN app is a good example of a mundane non-sexy tech decision.

    Overall nothing beats CSS and JavaScript for UI, but even in 2025 we cannot reliably push 60fps.

    • fidotron a day ago

      I disagree with you on a few specifics, but I think the more general question does become what should the Shopify app be like? Non sexy is, as you say, probably the right call.

      For mobile apps generally I cannot recall the last time I was actually impressed by one. The reverse is often true, such as with Sonos. Individual features (again Sonos, the calibration it can do) can be neat but experiences as a whole have gone off a cliff, React Native or not.

      • [removed] a day ago
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    • mdhb a day ago

      Flutter does 120fps no problems and has for some time now. Its also a lot nicer to work with Dart than Typescript.

      • phist_mcgee a day ago

        Entirely subjective and I would disagree with dart. JSX is one of the most important things react ever popularised in the frontend space.

breckenedge a day ago

Glad they spent some times discussing the downsides. I’m 4 months in to a Hotwire Native replacement for an unmaintained React Native app. The differences are stark and I could definitely see myself picking up Hotwire again for another project if given the same constraints, but I’ve had good experiences with React Native in the past too. Ultimately though I just do not like all the work that has to go into maintaining a large scale React codebase.

  • mattgreenrocks a day ago

    Curious what you meant by the last sentence there. Does React uniquely complicate maintenance as a codebase grows?

    • breckenedge a day ago

      Theres a constant churn of a bunch of dependencies. Devs add minuscule libraries all the time. And I think some of the best React libraries have been abandoned, which is kinda sad, but nice from a maintenance perspective.

      React very much feels like programming using only side-effects and that’s not really a fun experience IMHO. Performance issues are also somewhat difficult to spot in review and not very elegant to solve.

      It’s been a few years since I’ve used React Native so maybe things are better now?

      • tensor a day ago

        This is my experience with all javascript stuff these days. If you leave the codebase even for a few months now you're spending days updating it to all the new breaking library changes. Worse, if your tooling is out of date you're probably spending a week just fighting to fix/change/update the tooling. It's the most brittle tech stack I've ever had to work with.

      • nathanappere 18 hours ago

        "React very much feels like programming using only side-effects" this absolutely nails it.

      • nozzlegear a day ago

        > React very much feels like programming using only side-effects and that’s not really a fun experience IMHO.

        This is interesting and I like the way you've phrased it. Are you talking about React Native, or React in general? And do you use hooks?

        I like React on the web, but only when using hooks and only because I haven't found anything that I like more than it. I still find it tedious and overly hook-y¹. It also gives a lot of wiggle room for devs to shoot themselves in the foot with useEffect, like some of my previous clients have done.

        ¹ Hold on, I gotta pull in 18 hooks from across my project, npm dependencies and react itself before I can write the jsx in what would otherwise be a 10-15 line fooButton function.

      • gunian a day ago

        Any idea on whether this is a result of just npm/js ecosystem? Or just native frameworks in general?

        Trying to figure out if Flutter or RN would be best use of what little time I have left on this planet

    • HdS84 16 hours ago

      We maintain a few number of projects for clients - the apps are feature complete and will not change much in the next years. The goal here is to spend not much money on the apps but to keep them functional in the appstore. RN is somewhat cheaper up fron than native development or say flutter. Unfortunately, maintenance cost is high and difficult to predict. Why? Appstores are adding new requirements and increase API-level all the time. Support for that is often baked into new RN versions. Unfortunately, new RN versions often break things, which break libraries in turn. So you need to upgrade this morass and if you are unlucky, you need to redevelop huge swaths of your app because the lib now is deprecated /works differently / will never be updated to the new RN version.

      • dboreham 13 hours ago

        Also true for any large JS/TS application, in my experience. It's an emergent property of a developer culture that places no value on backwards compatibility.

  • seemack a day ago

    I was glad to see the discussion as well but it feels like the downsides were also very understated. Working on an RN app as a native dev requires a lot of cross-domain knowledge that isn't typical for a native dev.

  • Lucasoato a day ago

    Is there any benchmark about Hotwire Native screen response time?

  • Mystery-Machine 13 hours ago

    Great to see Hotwire Native here! I was asking myself would it be easier for Shopify to steer back more towards Rails ecosystem technologies. They went React / JavaScript full-throttle. JavaScript ecosystem seems so immature, and changing constantly with a huge maintenance burden. Rails feels really stable and Hotwire, although it's changing, feels stable. Stimulus was announced in 2018 I believe and they didn't have a single paradigm shift comparable to React's hooks, server components, etc.

grandinj 21 hours ago

So basically, as long as you are large enough to have direct contact with the upstream team, have a separate team to manage React Native itself, and have two separate teams for iOS and Android to manage stuff that needs native access, you are good.

eviks 15 hours ago

> We care very deeply about performance at Shopify

> We’ve achieved sub-500ms (P75) screen loads in the Shopify app

Pick 1.

Also interesting that this deep care about performance extends to blogs, where a simple animated image showing how awesome hot reload is causing a noticeable delay in scrolling

qazxcvbnm a day ago

By the way, is it Shopify’s open source policy to ignore outside PRs, or are they simply understaffed? My PR which addresses a major issue in one of Shopify’s big React Native libraries has received zero acknowledgement from Shopify for almost a year.

  • byroot 18 hours ago

    There’s no policy. The person or team owning an open source repo does what they want.

    Some are very closely watched, some were mostly just meant as extraction and not really expecting outside contributions.

mcsniff a day ago

Heh. Still no dark mode, it's almost as embarrassing as HN not having a dark mode -- yeah I said it.

https://news.ycombinator.com/item?id=34263628

Will another 10 years go by and there still won't be a dark mode for the app?

As someone who uses the mobile app basically every day, it is absolutely one of the things that bothers me, every single time I use it. That's not a good thing.

  • danpalmer a day ago

    It's constantly surprising to me that this one aspect of software appearance is a hill that the industry has collectively decided to die on.

    We can't agree to use colours that are unambiguous for colourblind folks, we can't agree to use sufficient contrast in our UIs, we can't agree to use big enough touch targets, most companies are truly awful at accessibility... and yet everyone wants dark mode, and most companies implement it. How much time have we lost as an industry making interfaces harder to read?

    • consumer451 a day ago

      Dark mode is an accessibility feature for myself, and many others I would imagine.

      Calling it dark mode might not be ideal though. We should probably call it something like system theme awareness, or anything that doesn’t make the reader to think “gee, that’s not the theme I like.”

      Prefers-color-scheme exists. It’s not that hard.

      https://developer.mozilla.org/en-US/docs/Web/CSS/@media/pref...

    • wiseowise 15 hours ago

      Before installing Noir on iOS, I always appreciated opening HN, or any website without dark mode, and feeling my eyes melting even on lowest brightness setting. Great and easy to read! Thanks for keeping my eyes I check!

humptybumpty a day ago

The quality standards are so low… half a second to switch screens is ok? Jesus!

Apple just keeps making billions and billions by focusing on UX, when other ”tech” companies are satisfied with this garbage.

  • JimDabell 15 hours ago

    > The quality standards are so low…

    Every so often they write an article talking about how great their several-years-long effort to switch to React Native is going, and every time I read it and come away with an even more negative opinion of React Native.

    https://news.ycombinator.com/item?id=34263896

    https://www.reddit.com/r/swift/comments/1bxogd1/have_you_con...

    • allenu 9 hours ago

      I've learned not to trust company technical blogs. They're all just marketing fluff intended to act as recruiting materials, and judging by the comments here, it's working. As your post highlights, taken in the greater context, it sounds like their decision to move to React Native was so slow going and the end-user experience is just okay.

      I suppose taken from the perspective of "We want to easily hire frontend devs that can easily be slotted in to work on the project and make impact on all platforms, including mobile" then it's a win, but at a cost in years and a degraded user experience. From a business perspective, probably a good move in the long run.

  • negative10xer a day ago

    I was just showing my team this article. We'd start getting warning alerts if our P75 page load times reached 500ms. I wonder if we're measuring load times differently.

    • gf000 a day ago

      It's also their P75 target load time.

  • Twirrim a day ago

    Agreed. The web driven enshittification of everything continues. It doesn't have to be this way. It really doesn't.

    If what you're using makes it this way, maybe stop using it? Stop drinking the kool-aid, get over your sunk cost fallacy and start thinking about what your end user experience should be, and work backwards from there, making decisions that guarantee you hit it. Don't choose the language or tool first and leave yourself constrained to only what is possible in it.

    • eviks 10 hours ago

      The sunk cost fallacy in this case would've prevented the switch from native. And what's worse is they've thought about user experience, "just" set the bar for it too low

methods21 a day ago

What would be amazing is if Swift and/or Kotlin could just be the 'native' language across both platforms and work at native speeds on both platforms.

  • te_chris a day ago

    https://skip.tools/ Swift can be!

    Saw this the other day and looks interesting

    • OccamsMirror a day ago

      Looks interesting! Thanks for the link.

      Not sure I agree with this though:

      > first-class development environment (Xcode)

  • wiseowise 15 hours ago

    World of subpar development experience. Truly amazing!

    Shitty native toolchains that constantly need to be updated (looking at you, Xcode), dumpster fire IDEs (both Android Studio, still don’t understand how Google managed to butcher IntelliJ like that, and Xcode), half completed libraries that are either deprecated or in alpha and, for some reason, in need of constant changes. Compile times in double digits for large projects. Stay up to date with shitty Gradle if you want to have semi sane development experience on Android (maybe they’ll finally roll out declarative version this year, but they said they’re still committed to original DSLs, so good luck to poor sob who will encounter mix of Groovy and Kotlin DSL). Wonderful world of single vendor languages where only interests of vendor dictate how language evolves (just how much resources and time were wasted on horrible KMP, because JetBrains wants to grab mobile market fully).

    Let’s gooo!

    • tarentel 10 hours ago

      I agree Xcode might be one of the worst IDEs I have ever used but at basically every company I've worked for the update cycle was maybe once or twice a year and for the most part was painless. There's been maybe one or two upgrades of Xcode in my ~13 year career that were a headache.

      I have no idea what libraries you're talking about but you don't really need to use any third party libraries to build a good iOS app. Unless you're doing something incredibly obscure most of the big/popular ones are very well maintained.

      • wiseowise 4 hours ago

        Android no longer has anything as part of standard SDK, everything is done as Androidx libraries.

neilv a day ago

Has anyone had a success with using "React Native for Web" for a Web-first consumer site (for desktop and mobile, including heavy plain text entry at times), but also being able to use the same React Native code to go to the iOS and Android app stores (when you reluctantly also satisfy those consumers who really-really want to install native apps)?

  • Signez 15 hours ago

    Bluesky. They use Expo on top of React Native, use React Native for Web (with a desktop and mobile), and for mobile native apps.

    Let's note that because the clients are fully open-source and on GitHub, people from Expo and React Native are helping the little team behind the clients improve performance over time: it's not their final form!

  • nwienert 12 hours ago

    Uniswap does this successfully. They share quite a lot of code between web and native, and their apps are open source. I made Tamagui, the library they use for sharing UI code, which goes much further than RNW in making this possible.

dep_b 18 hours ago

There's also the question of the amount of footgun you give to developers. While iOS is more performant than Android, Google gives Android developers much more guidance in best practices and patterns that help developers avoid issues around architecture, injection, state and threading.

I've seen many iOS projects overwhelmed by tech debt while its Android counterpart was still OK-ish. I don't believe this is coincidence.

So how hard is it to apply React Native the correct way? Having a dedicated team of dozens of engineers including native experts for each platform is different than your average 4-8 people dev (web, API, iOS, Android) team. Let alone if you only have people experienced in web doing the work.

When I build Swift applications the fact they have sub 500ms loads is not an achievement, they're simply already doing that without me trying. But I have found the right way to build iOS apps myself over the years, very little help from Apple.

assimpleaspossi a day ago
  • iammrpayments a day ago

    Thanks, I’ve been thinking about ditching react in favor of Svelte for a long time now, and this post cites enough reasons to justify it

    • wg0 20 hours ago

      I started with Svelte but ecosystem that React has is giant. Plus React Compiler is already being used in Instagram and Facebook so within this year, the virtual dom diffing would be a thing of past.

      • iammrpayments 16 hours ago

        The virtual dom is just part of the performance problem, the biggest problem in my opinion is the huge complexity that React adds, they solved part of it with useReducer and useSyncExternalStore, but I don’t think it will eventually be solved.

adityapurwa 18 hours ago

I really wanted to work with native SwiftUI, but the lack of hot reload and long waiting times for the preview to refreshes is just painful. React Native on the contrary, delivers good enough live feedback experience. I don’t enjoy React, but compared to waiting 10 seconds for preview changes and occasional “expressions too complex, break it down to smaller one” - I’d choose React. I do still trying to code natively on every XCode updates; just with the hope of it getting better somehow.

sumedh 2 hours ago

Which tools do they use to measure performance?

nitwit005 a day ago

> We’ve achieved sub-500ms (P75) screen loads

That's a difficult to interpret metric. If it's only being met 75% of the time, I'd tend to assume most features are much better than that, but some are never meeting the target, and there's no indication by how much.

morelish a day ago

I’ve noticed the app has gotten a lot slower and buggier on iOS in the last few years. Kind of wondered what they were writing it with.

griomnib a day ago

I really think aside from games, media editing, and other such heavy activities, 90% of apps are, or should be, web views. What they are doing makes a lot of sense.

tempfile a day ago

> Our apps are blazing fast (<500ms screen loads)

Hahaha we are absolutely cooked.

  • bigfatkitten 18 hours ago

    Load times I would've considered unsatisfactory in 2010 are "blazing fast" in 2025.

  • verdverm a day ago

    literally b/c the thermal effect on our phones?

treksis a day ago

Not sure at shopify size, but I highly encourage startups to use cross platform for mobile distribution. React native's OTA update alone is already worth for fast movers.

wg0 20 hours ago

Cannot recommend RN enough. One code base gives you three apps. Web, Android and iOS. With NativeWind, you have full Tailwind available to you and I had great success to the point where I have been thinking that I should be building customer facing web apps in RN (React Native Web + Tailwind) which at any time can be exported as native apps while already being a great web app.

justinko a day ago

Two words: Hotwire Native

  • grounder a day ago

    I'll look this up later tonight. Is Hotwire using the same approach as Capacitor / Ionic?

sirjaz a day ago

They could have written a MacOS and Windows app to go along with their web app with React Native but didn't. Such a missed opportunity

lvl155 a day ago

Had high hopes for Shopify at beginning of pandemic but it was all hype. Online shopping is still pretty much the same and in some ways regressed.

echelon a day ago

Why is the Slashdot logo on this article? I'm so confused. What's the relationship between Shopify and Slashdot?

  • jsheard a day ago

    That's Shopify Balance, which also has a /. logo for some reason. No relation to Slashdot.

    • echelon a day ago

      Ah, thanks! It's wild that they picked the same logo and the same color!

      • [removed] 12 hours ago
        [deleted]
      • jsheard 11 hours ago

        Oh it's meant to be a balance board / seesaw. Duh.

xyst a day ago

> Our apps are blazing fast (<500ms screen loads)

I frequently encounter Shopify e-commerce in the wild, and it’s my most disliked experience. From browsing the stores to checkout, it always feels clunky.

I always shrugged it off as iOS bullshit but now I know the real reason. It’s just slow enough to make you doubt yourself - it’s not the website, it’s probably my shitty {phone|poor internet|computer}

hsavit1 a day ago

So many of you are yapping about how the performance is not good enough. Yet none of you are talking about how Shopify literally could not develop their mobile app without it. The 3 minutes to compile the app just to do a trivial change makes it near impossible for devs to be productive. Hot reloading is what got me hooked to react native, I literally cannot allow for my brain to rot waiting for minutes waiting for Xcode to compile for a simple border radius change.

  • eviks 15 hours ago

    How did they manage to achieve the literally impossible thing for many years before this transition?

    > I literally cannot allow for my brain to rot waiting for minutes waiting for Xcode to compile for a simple border radius change.

    You can literally think about/edit other things while your simple border radius is being updated. No rot involved

    • hsavit1 8 hours ago

      this is an unserious reply. and if you are serious then you're likely not a frontend developer. often you want to test if a certain kind of hack fix works. your mind becomes glued to thinking about "does that fix it?" - hence why it's not easy to branch into a new line of thought then just come back to the change you pushed minutes ago. You're pretty much suggesting that the developer context changes into another thing for anywhere between 1 and 4 minutes and then context switches back to see if the build worked. The task that you'd be context switching into for 1-4 minutes will be interrupted by another thing and you'll likely make no progress doing it

  • sgarland a day ago

    And yet somehow, devs dealt with this tragedy for decades before us, cranking out software that was 100x smaller and 100x faster. Weird.

    • wiseowise 15 hours ago

      In what imaginary world you’re living, where basic Android app or iOS app are 100x smaller and 100x faster than RN?

      • sgarland 13 hours ago

        I was referring to PC programs, long before the term DX had become a thing.