Doing simultaneously. Udacity has less glitches. Codecademy hangs from time to time. Lots of traffic? Udacity also is longer and has more theory. But....

Doing simultaneously. Udacity has less glitches. Codecademy hangs from time to time. Lots of traffic? Udacity also is longer and has more theory. But.... Given the time and focus, Codecademy will catch up.