T-shaped expertise — broad knowledge deep in one high-leverage skill

T-shaped expertise means being an inch deep across many fields but a mile deep in one high-leverage area. You maintain broad curiosity and experience across domains — which gives you pattern recognition and the ability to synthesize unexpected connections — but you develop genuinely exceptional, world-class depth in a single skill that creates disproportionate value. The seven roles every entrepreneur must fill (entrepreneur, product designer, salesperson, marketer, technology guru, project manager, and recruiter) all benefit from this model. You don't need to be excellent at all seven — you need to be excellent at identifying which role is your T, and hire or build systems for the rest. The skill you go a mile deep in should be the one where your unique combination of experience and passion creates a competitive advantage no one can easily replicate.