[JamesBarney]

If you had one month to write an application on the MEAN stack and all you knew about two possible devs was one had 10 years of experience on winforms, and the other had 1 year of experience on the MEAN stack? Which do you pick?

I'd pick the MEAN developer everytime.

Sure in a year maybe the second one would be more productive. But there aren't any allergists that are a year away from productivity. Even if they hadn't learned anything in 10 years.

[digisign]

I'd let the person go that chose the mean stack, in favor of someone more experienced.

[flukus]

If you had a 1 month deadline and were still hiring I'd hope the guy with a decade of experience would see the looming tyre fire and select himself out of the running.

And you're kidding yourself if you think it takes a year to get up and running in whatever GUI stack was cool this year, the guy with 10 years of experience in winforms obviously knows a thing or two about picking stable mature technologies.

[arethuza]

If I had a deadline like that then I'd pick whichever one has a track record of delivering to tight deadlines - familiarity with a particular technology stack is going to help but isn't everything.