Threat modeling is the safeguard that should be implemented first as part of a comprehensive testing framework in order for application developers to detect potential vulnerabilities earlier during the Software Development Life Cycle (SDLC). Threat modeling is a technique that involves identifying, analyzing, and prioritizing the potential threats that may affect a system or an application, and designing and implementing the appropriate countermeasures to mitigate or eliminate the threats. A testing framework is a set of tools, methods, and processes that are used to test and verify the quality, the functionality, and the security of a system or an application. The SDLC is a process that involves planning, designing, developing, testing, deploying, and maintaining a system or an application. Threat modeling should be implemented first as part of a comprehensive testing framework, as it can help the application developers detect potential vulnerabilities earlier during the SDLC, and prevent or reduce the impact of the threats on the later stages of the development. Threat modeling can also help the application developers improve the security and the quality of the system or the application, as it can help them incorporate the security requirements and the controls into each phase of the SDLC, and to follow the secure coding standards and best practices.