I have a lot of weekend-ish side project on github (e.g. http://aperocky.com/cellular-automata/), but I also know a lot of capable engineers that does not have that. One of my favorite thing to look at for a candidate are their github, but unfortunately more often than not people don't have it or only CS-X01 repository exists. The interview is in no way affected by this as it is not an indication of weak technical ability.

But if someone does have it, it does get looked at, at least through me.