Raffaele Fragapane has done a great job with his Cult of Rig series with getting more people interested in low-level rigging and getting back to CS fundamentals when it comes to designing rigs. Something I found interesting in the way he did his rig features was using a script node to handle installation of callbacks. Script nodes, however, present several significant issues when it comes to production.
Instead of rambling on about it here, however, for once, I’m going to try something a little different; due to the length of this tutorial, I’m hosting it on Github instead, along with the example source code.
You can go ahead and read my thoughts on how I’d approach the same problem he tries to solve here.