I just want to say, it's always a nice feeling when I get all-green output from rspec and jenkins. The problem is that tests, like your code, are subject to the laws of entropy that comes from bit-rot.
So, I test things that matter and don't change too often - core business logic.
100% test coverage is just a goal, a bar to aim for.
And I'm totally with Zed Shaw when it comes to TDD - not worth it when you're still trying to get a full understanding of your problem domain.
It's better to try and work harder than not. Otherwise, your startup fails, or it really wasn't a startup in the first place (just a traditional company calling itself a startup).
Startups aren't for everyone. If you're a brilliant programmer who doesn't want to be pressured into quickly adapting, perhaps you should apply to Google instead.
So, I test things that matter and don't change too often - core business logic.
100% test coverage is just a goal, a bar to aim for.
And I'm totally with Zed Shaw when it comes to TDD - not worth it when you're still trying to get a full understanding of your problem domain.