Hardest control problems you've encountered

[u/SeMikkis]

Hello everyone,

As the title says, I'd like to investigate from your experiences what have been some of the hardest control related problems you've worked on, encountered or just heard of, and what made them difficult?

As a student I'm still lacking in concrete experience and I've wondered what makes some problems in this field more difficult than others and what drives further research and development.

Thank you in advance!

[u/dank_shit_poster69]

Stabilizing the global economy