I mostly disagree. Hiring senior devs who have worked at a variety of companies is the #1 way to improve your software. They don't have the same bad habits, pr

I mostly disagree. Hiring senior devs who have worked at a variety of companies is the #1 way to improve your software. They don't have the same bad habits, priorities, or biases as your existing team. They bring a diversity of culture that can give you the best of all worlds. If I trained my team myself, it would be a monoculture and we would probably still be writing PHP instead of abandoning it 10 years ago.