Just over four years ago we began one of our first collaborations – working with Stefan Kottwitz of the LaTeX Community forums and sites such as TeXample.net and pgfplots.net to provide a direct way for users of those sites to open up code examples directly in Overleaf (then called WriteLaTeX).
To get an idea of how it works, try clicking on the image below. It will open up in Overleaf for immediate editing online, just as if you'd clicked on the "Open in Overleaf" link on the example itself.