employed person; person who has found employment
Refers to someone who has secured a job, often used in contexts like new graduates entering the workforce or employment statistics.
The number of new graduate hires this year increased compared to last year.
The number of employed persons is easily influenced by the economy.
求職者 means 'job seeker' or 'applicant', someone looking for work, whereas 就職者 is someone who has already secured a job.
Compound of 就職 (shūshoku, 'finding employment') + 者 (sha, 'person'). The meaning is transparent from its components.