Sometimes, it's obvious a company is evil, because it's been in the news as evil, almost since it was founded. (Sometimes, they even get Hollywood's greatest speechwriter to make a movie about it, to re-spin the bad PR.)
Other times, it's less-obvious:
1. You don't have enough visibility into the company's operations, plans, or executives.
2. You don't know enough context of society and/or business, to understand how something innocuous-sounding is evil.
3. All's good on intentions and impact, but later the situation changes (company is pressured by market or investors, or someone falls into a bad influence yacht party scene, etc.),
Complicating this is that it's the norm (especially for startups) for a company to claim to be doing something positive for society:
1. Sometimes it's just marketing/brand convention that people go through, and don't think they have to take seriously (it'd be rude to say you just want to extract money).
2. Sometimes the founders/execs believe it, but with poor understanding of the problems and solutions (often by class sheltering, or simply not knowing the domain well enough).
3. Sometimes it's con artists and/or narcissists, who work the narrative to manipulate others, or to increase sense of personal glory.
I don't know a complete solution to this problem of detecting evil so you can avoid working for it.
I also haven't figured out a satisfying way to reconcile not wanting to work for evil, with wanting to have a comfortable life right now. Especially in "tech" right now, where a lot of bad practices have become so ordinary, we don't realize it. (And if someone called out the practices, we might get irritated like a 9th grade Economics fan, because that person who thinks that's a problem must be stupid, because we were told this is the way things are.)
Other times, it's less-obvious:
1. You don't have enough visibility into the company's operations, plans, or executives.
2. You don't know enough context of society and/or business, to understand how something innocuous-sounding is evil.
3. All's good on intentions and impact, but later the situation changes (company is pressured by market or investors, or someone falls into a bad influence yacht party scene, etc.),
Complicating this is that it's the norm (especially for startups) for a company to claim to be doing something positive for society:
1. Sometimes it's just marketing/brand convention that people go through, and don't think they have to take seriously (it'd be rude to say you just want to extract money).
2. Sometimes the founders/execs believe it, but with poor understanding of the problems and solutions (often by class sheltering, or simply not knowing the domain well enough).
3. Sometimes it's con artists and/or narcissists, who work the narrative to manipulate others, or to increase sense of personal glory.
I don't know a complete solution to this problem of detecting evil so you can avoid working for it.
I also haven't figured out a satisfying way to reconcile not wanting to work for evil, with wanting to have a comfortable life right now. Especially in "tech" right now, where a lot of bad practices have become so ordinary, we don't realize it. (And if someone called out the practices, we might get irritated like a 9th grade Economics fan, because that person who thinks that's a problem must be stupid, because we were told this is the way things are.)