I am active on StackOverflow and other Stack Exchange sites. I don’t usually post my questions and answers redundantly on afterecon.com, but I think this is a useful exception.
See this answer from a Stack Exchange site called The Workplace. It addresses whether it’s permissible to use work experience and even concrete code from work as an input to the production of code released as open source.
Note: I am not a lawyer and this is not legal advice.