Roughly, someone who at the start can work independently on an existing business-critical[1], medium-sized[2] app to first fix bugs without adding major tech debt[3] and then take features from planning to deployment/maintenance, and then ultimately (6-12 months, since we were a very small shop), independently steer architecture and be solo on call.

[1] hundreds of thousands in sales a day [2] around 10-50k LOC, but a far cry from the greenfield toy apps that bootcamp devs spend 90% of their time with [3] position: relative and z-index: 100 fixes many UI bugs, but if a dev has that as a main piece of their toolkit, you take on UI code debt or drag down the team to steer solutions in the right direction.