Some articles suggested that it's a set of skills when one can choose best-fit technology stack and get a project done. Some suggested that it's all about leading a team (but why do we have Team Lead then?).
Personally, I've been working as a web developer for 9 years professionally using front-end tech and back-end techs such as Go and Node.js. I can finish a website, a web service, SAAS project, choose tech stack, organize CD and CI, scale it up (not like AirBnB or Google but at a decent level), make the right decisions about testing and make the whole process work because I've done it before. Does it make me a Senior Developer?
What's your real world experience with a Senior Developer role?