The "normal" workflow I'm sure we've all lived is that design happens, then coding happens. A healthy workflow has back-and-forth between everyone involved in a project, including designers and developers, but still: The code is the final product. You design your way to code, you don't code your way to designs.
It was only a little over a month ago when it was news that Sketch 43 was moving to a .JSON file format. The final release notes drop the news quite blasé:
Revised file format
But Jasim A Basheer rightly made a big deal of it:
... it will fundamentally change how the design tools game will be played out in the coming years.
"enables more powerful integrations for third-party developers" is stating it lightly. This is what the fine folks at Bohemian Coding has done — they opened up Sketch's file format into a neat JSON making it possible for anyone to create and modify Sketch compatible files.