I've been working with RoR since 2009. I started to love ruby and rails at the times when developers had to support IE6 and prototype was a default js framework for rails. Since that time I've worked on many projects and seen a lot.
Most of the projects are startups but there are also big successful systems.
For most of the time I've worked as a team-lead (tech-lead) which means playing in a team. The biggest team I had was about fifteen people.
I got many legacy projects which made me an expert of refactoring and BDD but I also created many projects from scratch.
I think my biggest plus is that I worked on many (really many) projects. Every new project is some new experience. Hence I had a chance to get experience with most of the latest technologies and always be up to date. Implementation of particular feature is not the only thing I can do, I can also consult about which approach is better and give advise of how better to proceed.