1. meaningful
2. high impact
3. high authonomy
4. safe (low pressure, stress, etc.)
5. creative
And counterbalance it with lowpay to please market dynamic, something like a work for people with disabilities or requiring special assistance (which is done quite good in EU). I did try open source/own project, but the pay isn't guaranteed and I would like to pay the medical insurance/state pension and some basic (minimum wage) income to simply have peace of mind.