I've been promoted to Senior Software Engineer for about 6 months now and here are some of my thoughts on the journey
Getting there
Prior to my promotion I'd been working as a Software Engineer for about 2 years and my total experience in the industry was approximately 3.5 years. My company has job levels starting at 1 (Associate) going all the way up to 8 (Distinguished Engineer/Senior Director). After level 3 (Senior Software Engineer), employees are allowed to choose to either go for a technical path or a management path.
Each job level has some description of what kind of responsibilities are associated with it. I had a pretty good manager who understood my desire to be promoted and he was able to coach me on what management was looking for in a candidate who was nominated for promotion.
The promotion boiled down being able to demonstrate fulfillment of these areas:
Technical Do you ship code? Do you take ownership of your team/projects? Can you solve problems?
Leadership Have you contributed to improving the team? Do you delegate? Have you influenced within and outside of your team?
Now and the Future
The bump in responsibilities and ownership has been pretty significant and I think there's a lot of upskilling that would need to take place before my next step. I think the biggest change I've felt is that I end up in a lot more meetings and get involved in project decisions now. There's also been an increase in my sphere of influence in that I am seen as someone who takes responsibility over certain areas of our codebase and I also take part in improving the processes of our group organization which is one step above our team.