You're going to be working with less supervision, so you need to prove that'll work. Specifically you need to demonstrate you can work independently. This can

You're going to be working with less supervision, so you need to prove that'll work. Specifically you need to demonstrate you can work independently. This can be both job title ("senior software engineer" often maps to this) but it's also about a set of skills you want to demonstrate in your resume, cover letter, etc..