The ENISA Secure by Design and Default Playbook provides practical guidance for SMEs on integrating cybersecurity into the entire product development lifecycle. It presents clear principles, actionable recommendations, and repeatable practices for implementing secure-by-design and secure-by-default approaches throughout engineering, development, testing, release, and maintenance processes. The playbook helps organisations strengthen product security, reduce vulnerabilities, and support compliance with the Cyber Resilience Act (CRA).