The Open Source Security Foundation (OpenSSF), in partnership with Linux Foundation Training & Certification, offers a free online training course, Developing Secure Software (LFD121). Those who complete the course and pass the final exam will earn a free certificate of completion valid for two years.
The course is geared towards software developers (including DevOps professionals, software engineers, web application developers, and others) interested in learning how to develop secure software. It focuses on practical steps that can be taken, even with limited resources, to improve information security. The goal is to make it easier for these individuals to create and maintain systems that are much harder to successfully attack, to reduce the damage when attacks are successful, and to speed up response to rapidly repair vulnerabilities.