>> I also want to best position myself to become more experienced, take on new responsibilities, have input into key decisions, and be more visible to the lead

>> I also want to best position myself to become more experienced, take on new responsibilities, have input into key decisions, and be more visible to the leadership team and the rest of the business. Too late, you should've been doing this all along. For example, where you pitching in to help solve complex bugs or performance issues? Were you participating in deployments and monitoring the appications? Have you been helping with adminning third party apps like the ticketing system, CI servers, version control (git), etc? Were you building scripts to create minimal test database from nothing? Have you been implementing the tough parts of the system like payment processing? Bottom line is, if you really want to be "senior" you've got to put in the time. Sure some of these things are out of your control, but you've got to at least ask to take on more responsibility.