S3 Cross-Account Access Without Roles: A Practical, Role-less Approach to Bucket Sharing

https://bizzmarkblog.com/why-temporary-urls-and-expiring-tokens-break-at-scale-lessons-from-production-incidents/

Why role-less cross-account S3 access is worth your time If you run multiple AWS accounts or work with partners, you already know that managing cross-account access with IAM roles is the common pattern