It also depends on your deploy cycle. If you want to do continuous deployment (which seems to make development teams very happy) then you need great unit and in

It also depends on your deploy cycle. If you want to do continuous deployment (which seems to make development teams very happy) then you need great unit and integration testing. If you're ok with waiting a week or more between deployments manual QA seems to work well. As someone who's gone 'all in' on automated only testing I will admit that things that would have been caught by more human sanity checking slipped past me, now that I'm in an environment where manual QA blocks everything it feels like the excitement of shipping has been dimmed a bit. To anyone starting a new project I'd probably recommend more automated testing than manual and something closer to 12 developers per manual tester with developer only checking in code that includes automated tests.