It is very simple. Pick a nonprofit that has an exciting cause. Go on their website and look for openings. It’s going to need to be a very large org to have developers on staff as almost all IT needs typically are heavily outsourced to vendors. You can also work for one of these vendors.

Expected to leave massive amounts of salary on the table. You could be talking 50-150k less.

Non-profits do layoffs too, unfortunately. In some ways it's almost worse as there's less padding before they're losing money.

Try government.

Though I had no luck finding government jobs, because the red tape is ridiculous.