SPAs are harder and always will be (2013)

I am not defending SPAs, but the points you've made are not indicative of SPAs, they're indicative of bad software. This problem existed before SPAs were a thing. Remember ASP.Net pages where the whole page is wrapped in a giant <form> and you couldn't use the back button most of the time? This problem also doesn't exist with properly built SPAs (e.g., by using <a> for links, using the history API correctly, and designing a sensible UX). … ... There are plenty of legacy systems out there with frustrated users, and the "complexity" can be simplified if effort is invested to accomplish those goals. … ... It's especially dangerous when you have some "Find Order" UI, and then some executive chimes in with: "My group could really use some totals about the result-set. Since this is already 90% done..." Eventually you discover the "Find Customer" UI is abominably slow, having sacrificed the ability to find a customer for a bunch of quasi-reporting bells and whistles. … And given these are all well funded apps with good dev teams, doing extremely simple apps, it shows just how hard it is to get SPA right and I don't really think the difference is shrinking much at all. And I think this professionally too, a previous contractor turned part of the SaaS I'm working on at the moment into a SPA, and frankly, it's a nightmare (doesn't help it's durandal). They're so inflexible and so brittle. … And worse you now have to decide, do I add all those business rules and validation to the client too so I can make it super-responsive, or do I rely on my server to enforce all this, but then after every update I have to refresh the data, adding a potentially 500ms+ delay to the UI that is well in the realms of human detection (which is what happens in the Toggl case). … How do you do this with a traditional web site/app? > How do you enable snappy and responsive UIs when the network is slow? > How do you synchronize state between client/server? At worst you do it just like a traditional web site/app True, these are all problems that you deal with when building a single-page app, but the worst case scenario is that you end up with some of the same problems as traditional web sites. None of these are new problems that are introduced by the fact that you're building an SPA. … 1) instead of using browsers based on standards with hundreds of millions invested in developing them for things like routing, caching, history, etc, you are using ad-hoc amateur implementations of all those things that are full of bugs and unimplemented corner cases. 2) Instead of executing your code in a safe environment you control you are executing it in an unsafe environment on an unknown runtime that you have no control of. … There are some new things they must learn, so they may have a higher learning curve. Additionally the technology is really unstable. The build tools for example (webpack, babel, gulp, grunt) have changed tremendously and in breaking fashion now drastically over the past 4-5 years. Lots of legacy technology has stable tooling and so a more "seasoned" programmer may be a bit put off by that. Maybe that's this guys's problem.