Hi
i have mac air in this image

Befor updating to OS X El Capitan i got problem that the mac got stuck and i colluding start it.
When i entered the prepare mod i couldn't repair my Disk so i erased it and installed new OS X, but i lost every thing.
I am a developer and i have few projects on my mac so how can i recover my data?
I had no back up
Please help me
MacBook Air, OS X El Capitan (10.11), recover Hard Disk data