The Security team is unique in wanting engineers with both a coding and security background. If you are a classic SWE but possess security-fu then you're welcome to apply! My sub-team, AI Security, works on the security of our new AI features (mostly hardening infrastructure and making the data we train on anonymized). The other teams are focused around Application Security and Infrastructure Security (with some "endpoint" aka Mac security sprinkled in). The bar is really Senior and up. The company doesn't really hire below that unless you go through the internship program or have a strong personal referral for a team with an opening. (~5 years of experience being the rough rule of thumb unless you're already Senior at a 200+ engineer company.)
Figma is a fast-growing company working on securing AI features, model security, and access management across development stages. The security team spans areas like AppSec, Infra, and AI/ML.