Depending on the manager you get, unequal pay is rampant. HR will advise you to talk to them about pay, but they externally hire at a payscale of 5k to 30k more for similar roles with similar responsibilities. You will have the legacy knowledge, but when you try to work with HR regarding pay, they truly do not care and will make it sound like they cut you a deal when you promoted from an internal position to a different one.