There are relatively few technologies that I adamently refuse to work with in the IT industry.

1. Perl. Fucking hate it. Yes, you *can* write maintainable code with it; and some libraries are surprisingly pleasant to use. Emphasis on "some". That leaves *most* in the category of "out of the question." I simply refuse to work a job where I know ahead of time I'll be using Perl.

2. Javascript in general, and Node.js in particular. Fucking hate it. It was a significant contributor to my burn-out when I worked at Rackspace.
3. **ANYTHING** involving the use of MQTT. Full #*@#%^ing stop. MQTT solves **NO NEW PROBLEMS**, and only serves to create new problems. I'm screamed about this enough here already.
@vertigo Reading up on MQTT now. Good grief. I feel for ya.