Speed wise npm@5 caught up a lot of ground. Iirc it was the same a while ago. However, I always felt like the release was a bit rushed. I sticked to Yarn too tho.
We used to hire on Upwork regular for bigger projects and it usually was close to a gamble (for both parties). You get > 30 applicants easily if you pay decent wages and the cv's are usually quite non saying.
We gave people small, test projects to see if they could deliver and communicate effectively (they didn't know it was a test .. we paid them of course). Been having a decent experience on Upwork so far from the hiring side (we started this year). If you found resources on how to use Upwork more effectively, would appreciate pointers :)