I tend to think of it like this: Senior Developer: Comfortable leading a project, can understand architectural problems at the birds-eye-view but can also zoom

I tend to think of it like this: Senior Developer: Comfortable leading a project, can understand architectural problems at the birds-eye-view but can also zoom-in and get granular. Proves their worth by heightening others' output, not just their own. Developer (not senior, not junior): Provides lots of value to the team, in (likely) a narrow area of growing expertise. Can be assigned loosely-defined tasks and can "run" with them, and figure out problems independently. Asks for help when stuck, lends help to others. Proves their worth by sheer effort. Junior Developer: Needs guidance for most tasks. Needs tasks defined in detail if they're going to be left on their own to complete them. Asks a lot of questions. Proves their worth by being a sponge, learning very quickly, and being willing to do anything.