"Over the past several years, I've been more in a managerial role"

Dennis Ritchie's quote suggests that he has been transitioning from a hands-on function to a more managerial function over the past a number of years. This could imply that he has actually been handling more obligation and has been provided more authority to make decisions. It might also suggest that he has been handling more of a leadership role, directing and directing others in their work. It could also imply that he has been taking on more of a tactical function, looking at the huge image and making decisions that will benefit the organization as a whole. Whatever the case, it is clear that Dennis Ritchie has actually been transitioning from a more hands-on role to a more supervisory function over the previous several years.