At the time, we had been working on Webflow day and night for 6 months with no other income coming in, we had gotten rejected from YC a few months before, I was over $50K in credit (and medical) debt, and the Show HN was our last-ditch effort to get some traction before going back to our jobs.
The post did really well - we had the #1 position for most of the day, got over 500 upvotes, and in the resulting days over 25,000 people signed up for our beta list. This gave us the confidence to keep going and helped us get into YC for the next batch.
Since then, Webflow (https://webflow.com/) has grown into a profitable business with 400K+ users all over the world, billions of website requests served, and 25 employees (also all over the world). I'm not sure any of this would have happened if the Show HN would not have taken off the way it did.
TLDR: A+, would post again ;)
At first (in late 2012), we tried every single frontend framework available - including Backbone, Angular, Spine, and SproutCore (which ended up becoming Ember) - but they were all too slow for what we were doing. React wasn't yet a thing, and the only library that we found that worked fast enough was Knockout.js, so we went with that in the early days.
Since then, we've refactored 90%+ of the app (which is now approaching a million lines of code) to React/Flux/Immutable.js, with the remaining 10% not far behind.
We're hoping to post a lot more about our full stack in the future, especially since we're rolling out our dynamic website hosting stack worldwide (there's a lot of interesting S3/Lambda/CloudFront/Fastly goodies in there).
The biggest challenge is probably dealing with the huge array of different sites that people build, which range from small one-page marketing sites to huge 1000+ page dynamic web apps. Since Webflow is not template-based (like Weebly, Wix, Squarespace, etc) but rather allows designers to build up a site from scratch (including defining their own DOM nodes and CSS classes), we have to create JSON-based abstractions that need to work in a backwards-compatible way even as we add new features to Webflow.
Webflow is a much more professional tool targeted at web designers, freelancers, and agencies who create custom responsive websites, usually from scratch (or from a professional template as a starting point). That is, people who create websites for others. To be successful with Webflow, our users need to think somewhat like a developer (e.g. understand the box model, understand how CSS works in principle, etc), so the learning curve is a bit steeper.
For example, everything you see on https://webflow.com/ is built visually in Webflow and deployed to staging and production by non-engineers. There's a full database there with over 20 tables representing different content types, with a complex schema (e.g. blog posts, case studies, testimonials, job posts, templates, tags, etc), all the pages are custom responsive layouts - and all this was created without writing code.
None of this would be possible with Wix, Squarespace, Weebly, etc - since those are limited to their available templates. Most of the sites created in Webflow (see https://webflow.com/discover/popular for some examples) can only be recreated in Webflow or by writing code by hand, no other visual "WYSIWYG" builder comes even close.
You can think of Webflow as a much more evolved Dreamweaver, or a purely visual next-generation WordPress - minus all the code :)