Yelp

Change and progress are primarily driven by Engineers. If you have ideas and the drive to make them happen, you'll be happy here. It's remarkable how much, despite Yelp's size (engineering org is several hundred people), you can move the needle yourself.

The managing structure is light; managers don't get in your way and are sufficiently hands-on to understand what you're working on.

The product itself is "ethically harmless." While I'd have qualms about working for certain tech companies, I feel generally safe at Yelp. Everybody is constantly reminded that users should be protected and their data is sacrosanct.

The European branches (London, Hamburg) are fairly small; most of engineering works off San Francisco. Some people feel limited in the impact they can have in such a setting. Some people might have issues starting a bit late in the morning just so they can have late meetings with San Francisco in the evening. Other people might actually enjoy both things.