I have had to invent my own title for as long as I can remember because there aren't fixed roles/positions/titles at the company (In the sense that you are hired at a certain role/title.).
I'm now probably some kind of "Senior developer", or "Lead developer" or "Architect" or whatever. And I'd introduce me as such if someone asked. But I don't think this title exists in some database or contract anywhere. When we hire we some times call it "senior developer" just to mean experienced. But we don't have pay grades that means this new hire would necessarily be making more money than anyone not senior.