Is job security a thing that any programmer is worrying about? I'm a ruby developer and I recently sent my resume to a recruiter and had a new job 1 week later

Is job security a thing that any programmer is worrying about? I'm a ruby developer and I recently sent my resume to a recruiter and had a new job 1 week later and my impression was that there were 10 other listings from this recruiter who would have hired me had I finished their interviews. I don't have any particularly rare or specialized skills. Only 6 years ruby experience.