Developing secure software requires implementing proactive controls as outlined in the OWASP Top 10, a list of security risks and corresponding measures to protect against them. The proactive controls document provides a security overview for developers, understanding different layers of security risks, and how to protect against them. The top 10 proactive controls include defining security requirements, leveraging security frameworks and libraries, securing database access, encoding and escaping data, validating all inputs, implementing digital identity, enforcing access control, protecting data everywhere, implementing security logging and monitoring, and handling all errors and exceptions. These controls help build a secure product by identifying security risks early on and providing guidelines for developers to implement secure coding practices.