I try to look for work that causes the least possible harm rather than try to find something that causes no harm, because that's almost impossible. And also, if you find that job, the competition for it is so fierce can you really claim that by you having it you've put any more good into the world than if the next person had it?

Don't be disheartened. Like anything else in life you have to sort of slowly pivot in the right direction. If you've only just started thinking about this sort of thing and you're serious about it, it's going to get real uncomfortable. But it's totally worth it.