I think everyone in this thread is wrong. There is one thing I look for any time someone is looking to increase seniority in the organization and that's ownership. How much responsibility can you own with minimal oversight? Will you seek out the resources you need? Will you remove blockers. Will you do what you say? Will you get others to help you? Some people do this by producing lots of code and some of them do it by clearly documenting needs and concerns and getting others to be more productive. Usually it's both.