Staff augmentation is a flexible hiring model where organizations temporarily add external, skilled professionals to their existing teams to fill specific skill gaps or manage increased workloads. It allows businesses to scale quickly without the long-term costs associated with full-time employees, such as benefits, training, and onboarding. 

Engagements can be short-term or long-term and are typically paid on an hourly or project basis, making this approach attractive for fast-moving or project-driven environments. While staff augmentation offers agility for employers, it may be less appealing for job seekers who prefer permanent, secure roles.