Oxymoron Term: Junior Scrum Master

There are quite a few ways to go about answering this question.

One answer would be that it's not an oxymoron. I would say that it is true, because of the necessary knowledge and skills, that a Scrum Master is not an entry level position and requires someone with deep experience in technical skills (in Scrum, this means the type of work that the Developers are doing), product or service management, or organizational change and transformation. Having experience with agile and lean values, principles, and practices is also something that comes with experience and cannot be easily taught. I'd also suggest that you need sufficient depth and experience in something to be able to teach and mentor, which is something else that doesn't come without years of experience. However, once you have the experience of being Scrum Master - or any kind of agile coach - you could start at a "junior" level because you are just starting on the journey of coaching. As you gain experience as a coach, you may progress from a junior to a senior and beyond - it's useful to think about the amount of experience that a person has in a particular role. You may move from being a "senior" in one role to a "junior" in another because the role is different.

However, this argument only applies if Scrum Master is a job title. I could also say that you shouldn't have "junior" or "senior" Scrum Masters because the term "Scrum Master" describes a set of accountabilities and shouldn't be used as a job title. Although terms like "junior", "associate", and "senior" are appropriate for job titles, the organization should choose more appropriate job titles and avoid having "Scrum Master" or even "Product Owner", which are closely tied to the Scrum framework, as job titles for people in the organization. This is especially true since the work that the individuals do will extend beyond a Scrum Team and it would become harder to talk about Scrum Master as a set of accountabilities in the Scrum framework versus Scrum Master as a job function or set of organizational responsibilities.

The third thing that I'd add is that the Disciplined Agile Scrum Master and Disciplined Agile Senior Scrum Master certifications are Disciplined Agile certifications and not Scrum certifications. Although I have a good deal of respect for the folks behind Disciplined Agile and find it to be an extremely useful tool and model for thinking about work, the naming of their certifications leaves a lot to be desired. I don't know why they decided to include "Scrum Master" in the name of their certifications, since their framework doesn't use the term "Scrum Master". Their similar team role is "Team Coach", but even that has a very different definition. If I had to guess, I'd suspect it is to capitalize on people looking for Scrum Master certifications.

why do we have term like "Senior Scrum Master"

Because organizations love their hierarchies, even to the point that they shoehorn them onto the very change agents they've hired. There is an organizational gravity to be overcome.

Thank you Ian for your response! I liked the way you conveyed it :-)

Thank you Thomas for sharing your detailed thoughts.  I should not be thinking in terms of job title.  Those Senior/Junior prefix really relate to a job title, not the role itself. Why DASSM uses Senior prefix for SM remains a puzzle, but that's anyway outside the scope of this forum and my current learning endeavors. Thank you again!