Growth hacking is not a bag of tricks — it is a disciplined process of hypothesis generation, rapid experimentation, and data-driven iteration focused on growth metrics. This article traces the origin of the growth hacking movement from Sean Ellis through the growth teams at Facebook, Airbnb, and Dropbox. It covers the growth funnel (acquisition, activation, retention, referral, revenue), the process of running growth experiments, and the organizational design required to sustain a growth practice. The emphasis is on sustainable, ethical growth through product improvement rather than manipulative tactics.