As always it depends on the organization or team.

I have worked on teams where the title was nothing more than a title and didn't relate to their skill level or work ethic.

One of my favorite posts on the subject comes from John Allspaw: http://www.kitchensoap.com/2012/10/25/on-being-a-senior-engi...

An important part of the equation is a companies engineering structure. Camille Fournier has a great set of slides about creating structure earlier rather than later and why it is needed: http://www.slideshare.net/CamilleFournier1/how-to-go-from-st...