Valdi – a Cross-Platform UI Framework That Delivers Native Performance
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Cross-Platform UI FrameworksMobile App DevelopmentSnapchat
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Cross-Platform UI Frameworks
Mobile App Development
Snapchat
Snapchat open-sources Valdi, a cross-platform UI framework that compiles to native views, sparking discussion on its potential, design choices, and comparison to other frameworks like React Native.
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And more importantly, Snapchat seems like an app which could highly benefit from tight integration with native features (eg. camera, AR features, notifications, screenshot detection, etc.)
These companies have super talented engineers and can afford to invest in skunkworks projects like these when they can’t find any suitable options in the market.
And then you call it simple?
As for the "success of Snap could be attributed to how pixel perfect the app is". I think the success of Snap can be attributed to a lot of things. But if you took a look at how unoptimized the Android experience was in 2017 when it was taking off I don't know how you could call it pixel perfect.
The world or the us?
I don’t know a thing about Android camera SDK but I can easily see how this choice was the right balance for performance and quality at the time on old hardware (I’m thinking 2013 or so).
Users didn’t want the full quality at all, they’d never zoom. Zero latency would be far more important for fueling the viral flywheel.
Dating apps use awful quality versions of the photos you upload too. Seems to be good enough for most people.
Blame Google if you want to blame anyone. They could have mandated maximum shutter lag times (maybe they do now, I don't know).
I’ll take it
> it compiles directly to native views
There are significant trade-offs with this compiler at the moment: it uses much more binary size than minified JS or JS bytecode, and performance improvements goes from 2x to sometimes zero. It's a work-in-progress, it's pretty far along in what it supports, but its value-proposition is not yet where it needs to be.
Color me yellow.
When they first introduced video calls, schools had to close for a day.
Imagine then you come here and see someone calls it awful. Can't help but think its just an instance of "old man yelling at clouds".
By definition, the first app someone uses will be from their POV the most intuitive app ever. It will also be the least intuitive app ever.
xD
It's mostly subjective when talking UI, and a lot plays in too regarding the lack of competive platforms with different UI's.
If all the other apps look similar its because they copied it. This is like calling Citizen Kane boring.
> introduce feature
Phwoar, ground breaking UX design there!
> When they first introduced video calls, schools had to close for a day.
Which schools, where? Are they in the room with us now?
> For people who introduced themselves to tech with snap as one of their first apps, its the most intuitive thing ever
Point camera. Press button. Pick users.
Gotta try real hard to screw that one up, UI wise.
There's also views I can get into which I can't figure out how to leave, so I force close the app to get back.
I don't necessarily think that's a flaw of the framework, just how Snapchat designs their app.
We're heavily considering just having a website next year with a mobile app using webview, and then native code for the native notifications, GPS and healthkit / health connect.
I feel like AI is changing the equation, its nearly better to write your business UI 3 times one for each platform.
It’s called a “WebView app” and you can get a really good experience on all platforms using them. Just:
- don’t make any crazy decisions on your fundamental UI components, like breadcrumbs, select dropdowns, etc
- add a few platform-specific specialisations to those same components, to make them feel a bit more familiar, such as button styling, or using a self-simplifying back-stack on Android
- test to make sure your webview matches the native browser’s behaviour where it matters. For example, sliding up the view when the keyboard is opened on mobile, navigating back & forth with edge-swipes on iOS, etc
I also went the extra step and got service workers working, for a basic offline experience, and added a native auto network diagnostic tool that runs on app startup and checks “Can reach local network” “Can reach internet (1.1.1.1)” “Can resolve our app’s domain” etc etc, so users can share where it failed to get quicker support. But this is an app for small-to-medium businesses, not consumer-facing, and the HTML5 part is served from the server and cached. I haven’t thought much about what you might need to do additionally for a consumer app, or a local-first app.
AVFoundation on iOS especially.
A while ago saw a blog link on HN that explained how Apple uses it everywhere and we never notice it because they are done well. Of course I can’t find that link now, I summon the HN gods…
(In the context of "Apple has a private CSS property to add Liquid Glass effects to web content")
There's some jump from _a property exists_ to _it must be used_, but a massive one from _a property exists_ to _Apple uses it everywhere and we never notice it because they are done well_.
Aside from Apple’s apps (which imo are noticeably worse than the old ones, but that’s beside the point), what are some good WebView apps on iOS right now?
It doesn't look native but who even cares. I think when a UI sucks or is unintuitive or buggy then "it's not native" is a sort of catchall easy complaint. Native is a crutch. Sometimes it's a good crutch (accessibility etc). But that's more about developer efficiency and bare minimums of polish.
A webview app is by design bad. Webviews were made for one thing - web views.
I thought it was some legal thing about App Store competition.
On mobile the webview app experience is crap and it's immediately obvious that an app is not native. Simply nobody asks customers how they like it. The management assumes that as long as nobody complains and the users don't leave in droves, the experience must be impeccable.
> Definitely every one of these is sluggish at best on a very modern machine but they are also full of UI annoyances.
Done well as in: laggy, non-performant, break OS conventions and you can see elements load with the naked eye?
See App Store as an example: https://grumpy.website/post/0RsaxCu3P or Apple Arcade: https://grumpy.website/618 or...
I would be interested in any links to Webview apps that run really well, I’ve never seen one that I’m aware of but so many that I am aware of and are bad!
And between average native and average web view - it is night and day.
99% of web apps in desktop browser are laggy. And on mobile it feels like crap.
Sure if you are an expert in top1% you can probably get it working really good. But this is true only for 1 in 100 if not less.
https://github.com/aeharding/voyager
The app uses Ionic’s Capacitor, which to my rudimentary understanding is the webview-based upgrade of Cordova. I’ve had far fewer issues with this app than the likes of Bluesky (react native) and Discord (I think also react native but not sure).
The webview approach seems to be the only way for a one-person team to feasible provide a cross-platform app with an app-store presence. Another promising alternative to Capacitor is Tauri Mobile which does essentially the same thing, but mobile doesn’t seem to be a high priority for them.
It does seem that many RN apps do React (not native) components when they need to do something custom, which may explain my sub-par, non-native experience with the RN apps I have used.
- there's no touch feedback (ripple) on many of clickable components. Some that do have it look non-native, inconsistent and sometimes gets stuck
- the search bar on top app bar in `search` tab looks very non-native and non-standard (it's elevated on top of elevated app bar already)
- the lists look iOS-y, especially settings
- the settings list item has weird glitch where it loses background after touching (but not clicking)
- collapsing comments is pretty choppy (on a Samsung S25 so a pretty powerful phone)
- can't swipe down a bottom sheet (with post options/actions)
- it's just not android-y — the navigation is weird, the design is all over the place,
It's not unusable and it's a good tradeoff for a small team I guess. But this is nowhere near the experience a native app can provide, and has lots of small papercuts that would make for at least a slightly frustrating experience. It is a decent app don't get me wrong, but it's clearly not native
This kinda shows you how much effort and experience goes into getting an UI framework right, and the long tail quirks (of which there are a zillion) matter for UX, and while I appreciate they took on the task of breaking away from the browser, it's understandable why someone wants to ship an app on time and budget goes with a web based solution.
In case you're interested, the app is named "QuickÖV" - not relevant to anyone outside Switzerland, but just for trying it out: https://play.google.com/store/apps/details?id=com.billhillap...
The platforms provide more than enough capability to build basic WebView apps with minimal effort, and usually the DX is good.
Or you ship your HTML/JS and not just embed a URL?
However, from the user's side, this approach often results in a buggy, inconsistent experience that lacks the responsiveness and smoothness of a true native app that elusive "snappy" feeling (i know, I hate that word too)
Companies usually choose this route because it's cheaper, but that same "cheap mentality" often seeps into the overall product quality. Corners get cut, bugs get ignored, and long-term maintenance becomes a mess.
From a developer's perspective, it's a nightmare You're essentially expected to deliver on three platforms doing the work of three people for the same $ In theory, any web developer could handle it. In practice, you need to understand all the native platforms just to maintain some basic, stable integrations even with frameworks like React Native.
The result? Maybe 20% of your time goes into actual feature development, 30% into testing, and the remaining 70% into fixing obscure, platform-specific bugs while working overtime under pressure from cost-driven management.
In my experience, developers will do almost anything to avoid dealing with the native parts of this kind of setup those tasks usually get dumped on whoever is most "familiar" with native, because it's such a pain to handle.
And let's not forget QA testing across these hybrid layers is an absolute nightmare as well.
In the end, my view is simple: If a company can't afford dedicated native teams, they probably shouldn't build a native app. (Of course, smaller apps with limited complexity should be fine)
And it’s still usable as a website for everyone else on any platform.
Native experience for users, where the app appears in their app drawer/library. The app doesn’t disappear randomly like shortcuts do on iOS (maybe this is fixed now?).
Better DX for certain features, like notifications, storage, control of caching, local network device access, etc.
At least now I know who the offending devs are.
1. https://news.ycombinator.com/item?id=45250878
We have a React Native app that shares some code with a webapp, and that needs to do some geometry processing. So we're constantly playing the game of "will it interpret quick enough". Everything works fine in browsers, but in a RN app it often slows down to unusable speeds.
That said, platform lock-in is bad for business because it makes operations dependent on a single provider, but I have no delusions that a web front-end is better.
From an engineering standpoint, front-end web frameworks are less complete and require too many third-party libraries and tooling to assemble. From a UX standpoint, it's actually worse--almost every website you visit today spams you upfront with Google sign-in and invasive cookie permission requests that you can't refuse. But never mind that--from a purely business standpoint, a single platform accessible anywhere saves costs. Most importantly, however, the web is a "safe space" for deploying software anti-patterns without an intermediary entity (i.e an app store) to police your code, so you can do whatever the heck you want.
I'd wish for nothing more than the end of web and app front-ends in favor of purely structured data derived from natural language prompts by users. However, the more realistic mindset seems to be that: the front-end layer is such a high level of abstraction with a very low barrier to entry, so that its tech stack will be in constant flux, in favor of whoever's currently the best-financed entity seeking the most market share, the most developer mind-share, and the most behavioral control among its users.
At my last two jobs, when I did v front end work I had to coach designers through UX on a regular basis, because the designers did as much for the marketing department as they did for the development team.
Sadly, UX as a discipline doesn't get much love from most companies.
If you want to create good UX, I would look at whatever the big dogs are doing (Amazon, Meta, Google, et. al.) and not do that.
https://developer.mozilla.org/en-US/docs/Web/API/Web_Share_A...
https://developer.mozilla.org/en-US/docs/Web/API/Push_API
And not having to wait a week between bug fixes being deployed is a major selling point that native just can't compete with.
Lack of swipe for back on iOS is usually the easiest way to tell I'm looking at a web view.
But it's been about a decade so I'm due...
It's been a couple of years since I used it, but I think the Ionic framework has this feature.
https://ionicframework.com/
if you want to do something actually requires some compute, then suddenly this doesnt work so great
ex: youre prolly not going to want to edit images in JS
Anyone have any experience of doing this for a complex and long-life app?
Sounds like a nightmare that would increase friction and decrease development fun by x10 because of the huge overhead and tedium of having to keep your features and tests in sync across platform for every change you want to iterate on, and requiring developers be proficient at multiple stacks.
I get the usual complaints about bad webview implementations, but separate native codebases sounds like a prohibitively enormous tradeoff if most users only perceive the UX as being a little better than a good webview implementation. I feel like I'm missing something that native codebases is suggested as if it's a simple alternative, or this is coming from people that aren't actually involved in this?
Isn't reimplementing all your UI widgets, views, layouts and interactions for multiple platforms still a ton of work though? I'm not meaning people using things like React frameworks, but the suggestion of sticking to native only.
Also, you usually get better tooling in regards to instrumentation and the like.
When it comes to native stuff it get’s tricky. As always it really depends on the use case of the app. In our case we develop a navigation app using a native SDK to show a map + turn-by-turn nav + offline maps etc. This is probably the most non ideal use case for a hybrid app. We developed a few plugins to share data between js /native to initialize the map etc. However, the idea of sharing business logic is long gone. There’s so much stuff that’s happening natively and each time we implement it on Android, we have to switch to iOS and implement the Swift version of it.
Some others have also mentioned that a single person now has to know three platforms (iOS, android and Cordova (in our case with ionic + angular). This is true and the real downside. I’m quite familiar with iOS and android yet I’d never call myself a native iOS / Android developer. Yet, I’ve to write so much native code regarding permission handling, geolocation, threading (Ui/non-ui) and there’s always a ton to stuff happening from version to version (e.g. 16 KB Page Size on Android, iOS support for rotation the device/adaptive layout on iPadOS, etc). This is where a lot of time is lost. And the time is not only lost there but also with unmaintained outdated community plugins you suddenly need to understand and fix.
RN is a mess to get into, but once you've found a good stack you can really fly. We are working on a starter kit based off our experience that I think should represent the best possible starting point once it's released sometime before the EOY.
They always have to give up some basic or hidden conveniences that native controls get for free, so they always feel slightly different and "off" in a weird way which induces a constant vague annoyance while using them, like walking with a little pebble in your shoe, or a sitting in an chair that isn't balanced right.
It's funny how even after 50 years UI still isn't "solved" ..before writing a universal API, we don't even have universal consensus, or at least some kind of standards authority, on how controls should behave.
Hell not even users can’t agree, as would be seen on any comments about this topic, on stuff like whether lists should scroll up when swiping down, or scroll down when swiping up :')
I saw another comment calling it "webview app", which is also valid, but we call it "hybrid app".
Recent mid-tier phones are powerful enough that webview has a negligible impact on performance.
At the time such decisions are made, maybe the platforms couldn't do what was needed, but those platforms do tend to evolve, but not remain tracked.
Flutter to me has been one of the platforms that can quietly ship to multiple platforms as long as the parameters of what you're after can be accomplished in Dart, and if needed a bit of custom code for any particular platform.
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