PurposeThe aging of the population is changing the composition of the workforce in most developed countries. With increasingly older and age-diverse workforces, organizations need to redesign jobs to keep their workers healthy, happy and productive across the lifespan. In the current research, the authors integrate socioemotional selectivity theory and selection, optimization and compensation theory with job design to investigate how certain job characteristics influence the work engagement of older and younger workers.Design/methodology/approachIn a two-wave survey with age-diverse employees from multiple organizations (N = 372), the authors explore how autonomy and feedback contribute to the engagement of older and younger workers, depending on levels of task variety.FindingsIn the case of older workers the relationships between autonomy and engagement, and feedback and engagement are positive when task variety is low but non-significant when task variety is high. Conversely, in the case of younger workers the relationships between autonomy and engagement, and feedback and engagement are positive when task variety is high but non-significant when task variety is low.Research limitations/implicationsThe research contributes to the growing body of knowledge on aging and work, particularly the lifespan perspective on job design. Nonetheless, the correlational design warrants caution about drawing causal inferences.Practical implicationsThe findings inform managers on how to combine autonomy, feedback and task variety to design jobs that can engage the multi-age workforce.Originality/valueThe research is among the first to investigate the combined effects of different job characteristics on age-diverse employees' engagement at work.