When I hear this kind of comment I wonder about the mention of "junior" and "senior".
If I may suggest that the title 'junior' or 'senior' is artificial and generally unhelpful in the sort of quest you are on. If that sounds harsh I apologize, when I see development resumes I don't see "levels" I see strengths and weaknesses.
A developer that can pick up a frame work quickly and be productive in it is "strong", one who continually re-factors the problem so that they can re-use the framework they already know is "weak." A developer who can discuss the trade-offs between multiple frameworks in terms of solving the needs of performance, manageability, or resource usage is "strong", one who only knows the trade-offs and pitfalls of the framework they are most familiar with is "weak." Developers who are working on improving their understanding and craft are "strong", developers who are don't understand why their particular framework does something the way it does are "weak."
That is a lot of admittedly contrived examples but I hope they illustrate the kind of developer I look for when I'm hiring. If you have 10 years writing code I want to see a wide understanding of a lot of different systems, if you have 2 years writing code I want to see you understand the key design elements of the systems you are using, and have some idea of why those design decisions were made. It is the difference between being able to code, and code fluency.
So to answer your question, if someone wants "years of experience in a stack" then they may be using that as a filtering mechanism to get rid of people who are unsure of their abilities. I remember reading advertisements in 1998 for people with "5 years experience in Java" when Java had really only been released (early alphas in 1995). I wondered if they were just trying to hire folks who were part of the original team (which went back to 1991 :-). Talking to recruiters though, they were really looking for people who were so excited about Java that they had done an in depth dive on their own. Perhaps you are seeing something similar.
My advice to you is to lead with your strengths. If you have examples that demonstrate those strengths or projects which demonstrated them put them in too. Be honest with yourself about your weaknesses and think about ways to you can eliminate them. Be the strongest developer you can be and always work one ways to develop additional strengths. The rest has, in my experience, taken care of itself.
If I may suggest that the title 'junior' or 'senior' is artificial and generally unhelpful in the sort of quest you are on. If that sounds harsh I apologize, when I see development resumes I don't see "levels" I see strengths and weaknesses.
A developer that can pick up a frame work quickly and be productive in it is "strong", one who continually re-factors the problem so that they can re-use the framework they already know is "weak." A developer who can discuss the trade-offs between multiple frameworks in terms of solving the needs of performance, manageability, or resource usage is "strong", one who only knows the trade-offs and pitfalls of the framework they are most familiar with is "weak." Developers who are working on improving their understanding and craft are "strong", developers who are don't understand why their particular framework does something the way it does are "weak."
That is a lot of admittedly contrived examples but I hope they illustrate the kind of developer I look for when I'm hiring. If you have 10 years writing code I want to see a wide understanding of a lot of different systems, if you have 2 years writing code I want to see you understand the key design elements of the systems you are using, and have some idea of why those design decisions were made. It is the difference between being able to code, and code fluency.
So to answer your question, if someone wants "years of experience in a stack" then they may be using that as a filtering mechanism to get rid of people who are unsure of their abilities. I remember reading advertisements in 1998 for people with "5 years experience in Java" when Java had really only been released (early alphas in 1995). I wondered if they were just trying to hire folks who were part of the original team (which went back to 1991 :-). Talking to recruiters though, they were really looking for people who were so excited about Java that they had done an in depth dive on their own. Perhaps you are seeing something similar.
My advice to you is to lead with your strengths. If you have examples that demonstrate those strengths or projects which demonstrated them put them in too. Be honest with yourself about your weaknesses and think about ways to you can eliminate them. Be the strongest developer you can be and always work one ways to develop additional strengths. The rest has, in my experience, taken care of itself.