Security assurance and compliance in an Agile world

Has anyone found a good way to incorporate security assurance (I.e., new projects and service assessments) into an agile workflow and have any examples/resources?

My work is all waterfall where there are key milestones, artefacts and miss these and you push the timeline right. Trying to align this to an Agile project is always a bit messy but I scrape though. Just curious if anyone has tackled this problem.

agile assurance compliance cybersecurity security security assurance world