1. Experience with ever increasing levels of responsibility. To me senior engineers/developers should have a minimum of 8-10 years of real experience. The people calling themselves senior that have < 5 years to me almost always not senior level regardless of what title someone let them have -- but I have seen exceptions so you still have to base it on the person.
2. People skills, communication, respect for individuals and team
3. Minimally ego driven (everyone has an ego, just can't let it get in the way of good decision making)
4. Technically competent in design and architecture, but I don't care if you know how to write a B-Tree from scratch or implement some stupid algorithm. What I care about is you know when they are needed and what the design tradeoffs are, if you know that you can lookup the best implementation.
5. Team building skills, organization
6. I also look personally, for people who are de-escalators and calm. Working people up doesn't solve problems, calmly seeing facts and figuring out a plan is how to solve problems and lead a team.
