You can definately work nights and weekends, but most people don't need to hold down their regular local jobs.

Why would you keep your local $30k/y job when you can work full-time on Toptal for $80k/y?

Toptal covers hourly (min 10h/week), part-time (20h/week), and full-time (40h/week) engagements. Some months I've worked 60h/week (on my own accord).