What you want is cross-platform:

  - Web (IE, Safari, Firefox, Chrome, and older versions of those browsers)
  - Web responsive (When you access it from small screens or access the web from your phone's browser)
  - Android (old devices to recent ones)
  - iOS (old devices to recent ones)
  - And, eventually, get to a desktop app, ideally on windows, mac and linux.

Say you're the tech lead and you need to make a decision about the stack to support all these platforms, and you're a team of 2-3 devs, yourself included. What stack do you pick?

The fact is, only very rarely are you in a team of 2-3 devs and you need to support ALL of these platforms. If that’s the case for a small startup, serious strategic errors and lack of focus is being made by the founders!

Even Instagram didn’t even have an Android app until they were acquired, and then it still took them another couple of years to support web. Their focus was their success.

To be fair, Instagram didn’t have an Android app a long while ago. The Android market & demographic has changed a lot since, with high-end Android phones sporting great screens, cameras and costing nearly as much as the iPhone.

An Instagram launching today would see much greater pressure to be on Android sooner rather than later.

That’s true, and a good point that I should take into account when confronted with this decision in future.

Depends on what you're building. But sure, if you can remove the "cross-platform" spec. and say just build a desktop app on Linux, use whatever suits your boat.

Personally, I find it amazing to have one engineer builds a feature end-to-end from the server to the web/mobile devices by using the same language and re-using 90% of the code across all the clients.

Seconded this. The downside is you have to use C++ to beat Javascript performance. You can use Python of course but it is kinda slow.

The first version of Aether was in fact just that, Qt + Python. The performance was abysmal.