• Design and strengthen security in multi-account AWS environments, focusing on identity (IAM), networking (VPC, Security Groups) and data protection (KMS, Secrets Manager). • Implement automated security controls in CI/CD pipelines (CodePipeline, GitHub Actions, Terraform). • Configure and maintain AWS native security services: GuardDuty, Security Hub, CloudTrail, Config, Inspector, Macie, WAF, and Shield. • Establish continuous monitoring with CloudWatch, SIEM, and proactive alerts for anomalies or incidents. • Conduct internal pentesting, threat modeling, and security validation on APIs, serverless functions, and critical components. • Lead the detection and incident response (IR) strategy, including playbooks, drills, and basic forensics. • Ensure compliance with fintech regulatory frameworks (ISO 27001, SOC 2, GDPR, PCI DSS). • Collaborate with Platform, Data, and Core teams to ensure a 'secure by default' architecture.