DMARC compliance possible through both SPF and DKIM.
AmazonSES can be configured to sign using DMARC domain. See https://docs.aws.amazon.com/ses/latest/dg/send-email-authentication-dkim.html . Additionally, AmazonSES supports 2048-bit DKIM keys. Consider changing your keys if you are using 1024-bit keys. https://aws.amazon.com/about-aws/whats-new/2021/09/amazon-ses-2048-bit-dkim/
AmazonSES requires the use of a dedicated subdomain to achieve SPF alignment. Add 'include:amazonses.com' to this subdomain's SPF record. For more information, see: https://docs.aws.amazon.com/ses/latest/dg/mail-from.html