I think the missing piece is the intermediate / non-qualified title. Junior implies to me someone who requires frequent hand-holding and coaching even on small scale tasks. Senior on the other hand should require cross-functional communication skills as well as technical mentorship. There's a huge swath of developers who fit between those (solid individual contributors who aren't necessarily ready to lead a project or mentor).
"journeyman"? Might be too dated, or too gendered these days, but yeah... some 'not junior' term that just indicates they're "better" (experience or skill or both) than the juniors, but without all the expectations that 'senior' should bring.
For me, this most often comes up when acting as a reference for someone. The hiring person will ask me stuff, and often a 'senior' label question will come up. Almost invariably the person I'm acting as a reference for is beyond 'junior' connotations, and I think have to ask what the hiring person mean by 'senior'. Getting their definition helps me answer most effectively.
"Yeah, AB is pretty close to what you class as 'senior'. He's going to work well in a larger group with defined roles and a set schedule, which it sounds like you have."
"Well.. SJ is not 'junior' any more, but does need to have someone more senior to help mentor/check in on more advanced topics. If you don't have that - if this is a 'lone wolf' role, they may struggle some".
We have all the titles we need. We have junior for "that guy who can't do a fuckin' thing unless you tell him exactly what to type." We have senior for "that guy who can take a ticket and implement it." We have lead for "that guy who can take a business idea and implement it."
That should just be the title without prefix really, a Senior Developer should be providing more value than just ticket implementation.
These are just my opinions though, it differs from company to company. One place the difference between a Developer and a Senior Developer was a senior could be expected to own a feature and all the moving parts to get it deployed, eg: taking it to the board, organising all the approvals and business requirements with other teams etc. Other places senior just means "not junior" and the roles are the same, you just expect more talent from the senior.
