I know some may object to these. That's ok, this is my list. I'll answer questions though and I'm open to suggestions.
Here's my list, developed over 25 years working for companies, mostly startups:
Never work...
0. where you're not getting equity along with a paycheck, or where you can't ask the CFO how many shares are outstanding on a fully diluted basis, and get an answer, during your interview.
1. for a manager who is not an engineer, unless you're the CTO.
2. Think twice working for any "tech" company where the CEO is not an engineer, or technically proficient. (Tim Cook is technically proficient, Jeff Bezos is not.)
3. in an open office plan.
4. for a company that shows disrespect for employees in other ways. Companies try to hide so you have to look close.
5. for a company that uses cult behavior, eg: "magic phrases" like Amazon's "Today is Day One!!", or that has a management book that all employees are supposed to read (if said book is of the pop-management variety)
6. for a company that doesn't provide you a convenient parking space at their expense (you should be working remote anyway!)
7. for a company that doesn't provide flex hours. Flex needs to really mean flex. Midnight to 8AM is an acceptable work schedule.
8. for any company with standup meetings, or other pointless meetings. (yeah yeah, all of the previous "SCRUM" teams have been "doing it wrong", so that just means nobodies doing it "right")
9. on a team where mandatory meetings happen more than twice a year
10. for a company that employs stack ranking, in any form.
11. for less than 3 weeks of vacation a year
12. for a "starter" salary that will be "made up later", unless this is a startup and you're getting a significant chunk of equity- eg: shares valued at most recent round of investment, or a $1M valuation if no investment, EXCEEDS the lost income.
12. for equity with a vesting schedule with an initial cliff longer than 90 days, (30 days is appropriate)
13. for equity with a vesting schedule over 4 years (and only 4 for > %5 equity)
14. for a company that has taken money from dishonest or unethical VCs (I know a lot of the bad ones but check "the funded" for reviews)
15. for a company that doesn't hire ops engineers, but expects developers to be "on call"
16. for a company that has a lot of restrictions about vacation and doesn't treat it as real (eg: you don't get all your days when you leave, bad PTO policies, etc)
17. in any office without adequate bathrooms, this includes any buildings where people are packed like sardines. combine the gender ratio of tech companies with more than %100 occupancy and the bathrooms are insufficient
18. in any setup with less than a dual thunderbolt display, or single 35"4k monitory.
19. on windows on a regular basis
20. where my development machine can't be a Mac