Mateusz Kowalski Senior DevSecOps Engineer
San Francisco, CA • mateusz.kowalski@gmail.com • +1 415-555-0129
Profile Summary
- Senior DevSecOps Engineer with 7 years of experience operating cloud-native DevSecOps environments across container-security SaaS, incident-response SaaS, and developer-tooling scaleups, specializing in CI/CD security gates, IaC and container scanning, and supply-chain hardening.
- Solid technical background across CI/CD pipelines (GitHub Actions, ArgoCD), AppSec scanning (Semgrep, Snyk), IaC scanning (Checkov), container security (Trivy), secrets management (HashiCorp Vault, GitGuardian), policy-as-code (OPA), supply-chain security (Sigstore Cosign), and languages (Python, Go) with strong fundamentals in shift-left scanning, automated guardrails, and developer-friendly remediation paths.
- Deep expertise in shift-left scanning gates, paved-road golden pipelines, policy-as-code enforcement, and SLSA-aligned supply-chain controls, leveraging methodologies such as risk-based scanner tuning and secure-default templates and security champions to drive fast, safe, and developer-friendly delivery.
- Engaged collaborator working cross-functionally with Engineering, SRE, Platform, and Security teams in security-as-a-product environments, contributing to RFC reviews, threat-modeling sessions, and post-incident retrospectives with a developer-first, ownership-first mindset.
- Emerging leader who shares technical excellence and fosters a culture of developer-experience obsession and signal-over-noise discipline through paved-road authoring and security office hours, while leading DevSecOps guild and security-champions sessions and authoring widely adopted scanning-pipeline and policy-as-code templates.
Technical Skills
- CI/CD & Delivery:
- GitHub Actions (composite actions, reusable workflows), GitLab CI, Jenkins, CircleCI, ArgoCD, Flux, security gates
- AppSec Scanning (SAST/DAST/SCA):
- Semgrep, SonarQube, Checkmarx, OWASP ZAP, Burp Suite Enterprise, Snyk, Dependabot, Mend, secure code review
- IaC Security:
- Checkov, tfsec, KICS, Terrascan across Terraform, CloudFormation, Bicep, Pulumi, Helm, and Kubernetes manifests
- Container & Kubernetes Security:
- Trivy, Grype, Snyk Container, OPA Gatekeeper, Kyverno admission policies, Falco runtime, distroless / minimal base images
- Secrets Management & Detection:
- HashiCorp Vault, AWS Secrets Manager, Doppler, 1Password Secrets Automation, GitGuardian, TruffleHog, Gitleaks
- Policy as Code & Guardrails:
- OPA / Rego, Kyverno, Conftest, HashiCorp Sentinel, admission control, automated policy-violation reporting
- Supply Chain & Cloud Security:
- SBOMs (Syft, CycloneDX, SPDX), Sigstore Cosign image signing, SLSA framework, Wiz, Prisma Cloud, Orca, Lacework
- Languages & Automation:
- Python, Go, Bash, Rego, Terraform, Kubernetes Operator SDK, GitHub Actions composite actions, Helm
Education
Work Experience
- Owned the DevSecOps program for product engineering across the container-security product engineering org supporting 540+ engineers, embedding controls across CI/CD scanning gates, IaC and container security, and supply-chain controls across 280+ CI/CD pipelines.
- Ran the AppSec scanning program integrating Semgrep, Snyk, and OWASP ZAP, applying Semgrep SAST rules per repo type, Snyk SCA + license-policy gates, and OWASP ZAP staging-environment DAST, triaging 6,200+ findings per quarter and cutting false-positive rate from 41% down to 8%.
- Embedded IaC scanning gates using Checkov with Checkov on Terraform and Helm in PR-blocking mode, tfsec for module-level guardrails, and Kubernetes manifest linting in CI across 190+ IaC repos, cutting critical misconfigurations by 78%.
- Drove container and Kubernetes hardening using Trivy, Trivy image scanning at build and runtime, OPA Gatekeeper admission policies, and Falco runtime detection for privileged exec, protecting 1,400 production images and 12 production EKS and GKE clusters.
- Owned secrets management and detection with HashiCorp Vault and GitGuardian, including HashiCorp Vault for dynamic AWS credentials, GitGuardian pre-receive hooks across all repos, and break-glass rotation and access-review workflows, with 380+ secrets-leak attempts blocked in CI.
- Built policy-as-code guardrails on OPA, covering Rego policies for Terraform plan output, Kyverno cluster policies on Kubernetes admission, and Conftest gates on Helm charts before deploy, blocking 97.2% of non-compliant deploys across the engineering org.
- Stood up SLSA-aligned supply-chain controls with Syft-generated SBOMs in CycloneDX format, Sigstore Cosign-based Sigstore Cosign image signing and verification, and dependency-provenance attestations at build time, signing 100% of production images and Helm charts and achieving SLSA Build Level 3 for the core image-build pipelines.
- Built the cloud-security automation program across 84 AWS accounts, including Wiz CNAPP findings auto-tagged to repo owners, Lambda remediations for tagging and encryption drift, and AWS SCP guardrails for new account onboarding, cutting cloud-misconfig MTTR from 11 days to 2 days.
- Built the developer-enablement and security-champions program with paved-road golden pipelines for new services, secure-coding workshops aligned to OWASP Top 10, and quarterly security-champions retros, onboarding 22 security champions across 9 product teams and lifting new-service onboarding to the secure-default pipeline lifted from 38% to 92%.
- Ran the vulnerability-metrics and continuous-improvement program with aggregated findings across SAST, SCA, IaC, and container scanners, risk-based prioritization using exploitability and asset criticality, and monthly tuning cycle to retire noisy rules, cutting mean time to remediate critical findings cut from 21 days to 4 days and holding escape rate to prod under 0.7% across 18 months.
- Worked closely with Engineering, SRE, Platform, and Security teams to coordinate quarterly DevSecOps RFCs, threat-model facilitation, and incident postmortem actions, authoring 14 DevSecOps playbooks that shaped the team's standard playbook and mentoring 4 junior DevSecOps engineers through their first paved-road launches.