Beyond GDP Development: Measuring Prosperity as a Systems Outcome argues that economic output is too narrow to serve as a full measure of development because societies do not prosper through production alone, but through the interaction of human capability, institutional quality, distribution, and ecological stability. The article reframes the beyond GDP debate by showing that GDP remains useful as an indicator of economic activity, yet becomes misleading when it is treated as a proxy for overall wellbeing or long-run progress. It explores the limits of GDP, the capabilities approach and human-development tradition, the role of institutions and inequality, and the need for a broader measurement architecture that captures whether growth is actually strengthening the systems that make prosperity durable. Its central claim is that development should be measured not as output alone, but as a systems outcome.