We use AWS Shield Standard, one of AWS's services, for DDoS attack protection, along with AWS WAF for API layer protection, and have implemented Amazon GuardDuty for threat detection mechanisms.
Teachme Biz uses AWS Fargate as its application execution environment, and OS layer protection is implemented by Amazon Web Services (hereinafter referred to as AWS), so we cannot provide specific information about OS layer protection measures. However, we utilize infrastructure that complies with PCI DSS level 1, ISO27001, ISO27017, SOC1, SOC2, SOC3, and other standards.
Additionally, all our databases, storage, and email servers use AWS managed services (Amazon Aurora, Amazon S3, Amazon SES), so they are similarly managed by AWS.
For more details, please refer to the whitepaper provided by AWS:
https://d1.awsstatic.com/whitepapers/AWS_Fargate_Security_Overview_Whitepaper.pdf