A startup founder asked me last week: "Can one full-stack developer build my whole product, or do I need a team?" My answer: "It depends on the product." For an MVP, one strong full-stack developer can do all of it. Frontend, backend, database, APIs, deployment. I've shipped 10+ products this way. The advantage isn't cost. It's that one person holds the whole system in their head. No gap between the frontend dev who assumed one thing and the backend dev who built another. No week lost to a spec meeting. Where one developer stops being enough: → Two features need building in parallel, and both are urgent → The work needs a real specialist like ML training, native mobile,  heavy infrastructure → You're past product-market fit and growing faster than one person  can maintain → Design is your differentiator, so you need a designer, not a  developer with taste Until you hit one of those, adding developers usually slows you down. The question isn't how many developers you need. It's whether the scope is narrow enough that one can finish it.