Software Performance Risk Management defines a governance discipline for determining whether modern software systems are survivable before they are allowed to operate at scale. Rather than focusing on performance metrics, tools, or observability, this book addresses the structural and organizational risks that arise from architectural decisions, dependency concentration, trust assumptions, and the absence of accountable authority. The work reframes performance not as speed or efficiency, but as a form of business risk governance, where survivability, blast radius, and recovery feasibility must be evaluated and owned at the executive level. It introduces a formal language for exposure, risk surfaces, and non-delegable responsibility, providing governance artifacts that allow organizations to reason about failure boundaries before incidents occur. Written for engineers, architects, and senior leaders, the book draws clear jurisdictional boundaries between performance engineering, observability, reliability, and incident response, and explains why none of these disciplines can govern survivability on their own. Case studies illustrate how well-instrumented systems still fail catastrophically when authority, accountability, and structural risk are left unmanaged. Software Performance Risk Management is not a methodology, framework, or tooling guide. It is a foundational governance text for organizations that rely on complex digital systems and must make explicit decisions about which risks are acceptable, which dependencies are tolerable, and who is responsible when survivability is at stake.