Imagine a team building a simple feature: an endpoint to let users download their invoices. The implementation is straightforward: check the user is authenticated, fetch the file, and return it. It passes code review, tests are green, and it ships. A few weeks later, someone realizes you can tweak a parameter and download another user’s invoice, and the team now has to rush to fix this security issue. No software engineer sets out to write insecure code. However, stories like this one keep happening, and if you think about it, for the team building the feature, nothing “looked” insecure during development, and that is because no one had clearly defined what secure meant for that feature in the first place. This is the real gap AppSec engineers fill. Their job isn’t just to run tools and share the findings with engineering, but to define what “Secure” means in the context of what is being built by helping teams ask the right questions early: Who should have access to this data? What could go wrong?…