Felienne is associate professor at the Leiden Institute of Advanced Computer Science at Leiden University, where she heads the PERL research group, focused on programming education.
On Saturdays she teaches children programming in a local community centre. She is one of the organizers of the CurryOn conference, which aims to bridge the gap between industry and academia. Felienne was also one of the founders of the Joy of Coding conference, with a similar goal, which she organized for 6 years. Since 2016, she has been a host at SE radio, one of the most popular software engineering podcasts on the web. When she is not coding, blogging or teaching, she is probably knitting, running or playing a (board)game.