When you liked the role of Senior Software Engineer, was the situation that you could trust that others in the company were doing a good job of covering the res

When you liked the role of Senior Software Engineer, was the situation that you could trust that others in the company were doing a good job of covering the responsibilities outside your scope? Or was it because the scope was nice, and you didn't much care what happened outside the scope? (Both are valid ways that people look at jobs, at different times, and in different situations. Just interested in anecdata and insights into how I should think about hiring.)