A senior can write, test, deploy, and possibly maintain a scalable microservice or similar sized project without significant hand-holding in a reasonable amount of time.
A junior might be able to write a method used by a class but is still learning significant portions and concepts either in the language, workflow orchestration, or infrastructure.
A principal knows how each microservice fits into the larger domain they service, whether they understand all services and all domains they serve.
A staff has significant principal understanding across many or all domains an organization uses, builds, and maintains.
AI code assistance help increase breadth and, with oversight, improve depth. One can move from the "T" shape to "V" shape skillset far easier, but one must never fully trust AI code assistants.
Roughly:
A senior can write, test, deploy, and possibly maintain a scalable microservice or similar sized project without significant hand-holding in a reasonable amount of time.
A junior might be able to write a method used by a class but is still learning significant portions and concepts either in the language, workflow orchestration, or infrastructure.
A principal knows how each microservice fits into the larger domain they service, whether they understand all services and all domains they serve.
A staff has significant principal understanding across many or all domains an organization uses, builds, and maintains.
AI code assistance help increase breadth and, with oversight, improve depth. One can move from the "T" shape to "V" shape skillset far easier, but one must never fully trust AI code assistants.