Hi, I'm Ker Xiang Teh.

One of the largest privately held companies in the United States. Member of the AppSec team within Digital Security Architecture & Engineering.

• Program ownership: owned the enterprise DAST program (scanner migration, authenticated scanning for Okta-protected apps, Vault-managed scan credentials) and core vulnerability management pipeline standards.
• Security reviews: led external live-testing of an API gateway externalization (WAF bypass, fail-open, Burp payload testing, container reachability, TLS), a code review plus UAT of a data self-service portal, and threat models for web, backend, and cloud systems.
• Guardrails at scale: Terraform-managed scanning infrastructure with OIDC and IAM permission boundaries, GitLab CI/CD security checks, shared scanning templates, and secure-by-default AWS and GCP patterns.
• AI-augmented automation: Python Lambda forwarders and parsers that normalize findings from multiple DAST and SCA tools into one platform, with automated triage, retests, and remediation guidance.
• LLM security: extended RapiDAST with Garak to security-test an internal LLM application endpoint.
• Incident response: triage and guidance for npm supply-chain campaigns, a GitLab MCP server authentication bypass, and zero-day threat hunting.
• Enablement: resolved 400+ AppSec tickets, rotated on-call for Semgrep, Vault, certificates, and DAST, mentored new team members, and wrote onboarding docs that let teams self-serve.
• Cloud posture: reduced GCP false-positive volume, tightened IAM and RBAC, and restricted external GKE control-plane access.

• Training: led workshops and training sessions for level 1 and 2 tutors, and evaluated tutor performance with constructive feedback.
• Code review: reviewed and optimized student code, coaching on quality standards and best practices.
• Tutoring: tutored Calculus and Computer Science courses, staying current on new languages to support course needs.

• Mentorship: mentored Tier 1 field technicians and led technical issue resolution for enterprise clients in an MSP environment, analyzing server diagnostics and third-party web application issues.
• Project leadership: led multiple projects in a fast-paced MSP environment, meeting deadlines and documenting issues and resolutions in internal knowledge bases.
• Systems engineering: optimized server configurations with the Microsoft Deployment Tool, focusing on Active Directory and DNS/DHCP.
• Previously Field Technician (Nov 2018 - July 2019): supported remote users and exceeded weekly ticket closure targets by 20% through new tools and process improvements.

• Network security: configured and optimized Cisco ASA firewalls, deployed intrusion detection systems, and maintained NAS devices for enterprise clients.
• Backup and recovery: designed backup solutions for data centers and remote sites, and automated server backup processes to reduce manual errors.
• Secure operations: supported secure network operations including VPN and access control management.
• Previously Intern (June 2016 - June 2017): ran update and maintenance projects and designed, installed, and configured secure client networks, including routers, switches, and firewalls.