I don’t buy it. As software developers we learn technologies for breakfast. We learn them, and then we forget them. We recollect the wisdom gained and apply it in our next gig using a different technology. It works for mobile development, for frontend, for backend, for infra, for almost anything.
I have worked for years with PHP, Apache, Ansible and MySQL. Nowadays not anymore. And in 7 years I’ll be using something else. Learn the fundamentals (which is not a one-time job, btw) and you’ll be fine. If someone asks for technology X in their job offers when you know Y, but you know you won’t have difficulty in learning X, just take a few days in learning X and then put it in your CV. You’ll get pass HR screening and then you’ll have a chance to explain in tech interview that your are more of a technology-agnostic dev. You’ll do fine.
I have worked for years with PHP, Apache, Ansible and MySQL. Nowadays not anymore. And in 7 years I’ll be using something else. Learn the fundamentals (which is not a one-time job, btw) and you’ll be fine. If someone asks for technology X in their job offers when you know Y, but you know you won’t have difficulty in learning X, just take a few days in learning X and then put it in your CV. You’ll get pass HR screening and then you’ll have a chance to explain in tech interview that your are more of a technology-agnostic dev. You’ll do fine.