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 securing cloud-native SaaS delivery pipelines for container security and retail e-commerce, specializing in pipeline scanning, software supply chain security, and Kubernetes hardening.
- Daily hands-on work across CI/CD (GitHub Actions, Argo CD), code and dependency scanning (Semgrep, Snyk, OWASP ZAP), IaC scanning (Checkov), containers (Trivy, Kyverno), secrets (HashiCorp Vault, GitGuardian), signing and policy (Sigstore Cosign, OPA/Rego), and scripting (Python, Go), built on least privilege, fast feedback in the pull request, and fixes a developer can ship the same day.
- Deep expertise in merge gates that block only on real risk, SBOMs and signed builds, Kubernetes admission control, and risk-based vulnerability triage, following the NIST SSDF and SLSA to deliver daily releases that still clear SOC 2 and ISO 27001 audits.
- Works closely with Platform Engineering, SRE, Product Security, and Compliance at a security vendor that runs its own product in production, joining design reviews, release planning, and incident calls whenever a change touches the build system or the clusters.
- Senior engineer who sets the standard for findings that come with a fix and scans that finish before the unit tests do through paired fixes and code reviews, and runs the security champions group and monthly DevSecOps office hours.
Technical Skills
- CI/CD & GitOps:
- GitHub Actions, Argo CD, GitLab CI, Jenkins, Helm, reusable workflows
- SAST, DAST & SCA Tools:
- Semgrep, Snyk, OWASP ZAP, CodeQL, SonarQube, Dependabot
- IaC & Cloud Posture:
- Terraform, Checkov, KICS, AWS, AWS Security Hub, Wiz
- Containers & Kubernetes:
- Trivy, Kyverno, Amazon EKS, Falco, Docker, distroless images
- Secrets & Identity:
- HashiCorp Vault, GitGuardian, AWS Secrets Manager, Gitleaks, AWS IAM, OIDC federation
- Supply Chain & Policy Engines:
- Sigstore Cosign, OPA/Rego, Syft, CycloneDX, SLSA, Conftest
- Languages, Standards & Tracking:
- Python, Go, Bash, Jira, OWASP Top 10, NIST SSDF
Education
Work Experience
- Added Semgrep SAST, Snyk dependency checks, and OWASP ZAP scans of staging to 210 GitHub Actions pipelines, blocking a merge only on high-confidence findings and cutting the false-positive rate developers saw from 38% to 7%.
- Moved 140 services from static AWS keys to HashiCorp Vault dynamic credentials and OIDC roles in CI, and put GitGuardian on every push, catching 260+ secrets before they reached a default branch in 2025.
- Signed every production image and Helm chart with Sigstore Cosign, attached Syft SBOMs in CycloneDX format to each release, and verified signatures at deploy time, reaching SLSA Build Level 3 on 34 image pipelines.
- Ran Checkov on every Terraform and Helm pull request across 120 repos and published secure default modules for EKS, S3, and IAM, cutting critical misconfigurations that reached production by 74% in a year.
- Hardened 14 Amazon EKS clusters with Trivy scans in CI and the registry, Kyverno admission policies, Falco runtime rules, and distroless base images, cutting critical CVEs in running images from 410 to 36.
- Wrote 60 OPA/Rego policies run through Conftest on Terraform plans and Kubernetes manifests, with exceptions that expire in Git, and reused pipeline logs as SOC 2 evidence, cutting audit prep from 5 weeks to 6 days.
- Built a Python triage service that merges duplicate findings, ranks them by EPSS, CISA KEV, and runtime use, and files Jira tickets for the owning team, cutting time to fix critical findings from 26 days to 5 days.
- Started a security champions group of 24 engineers and a golden pipeline template with every scan already wired in, raising its use on new services from 35% to 94%.
- Added Checkmarx SAST and Snyk checks to the Jenkins pipelines behind the Gap, Old Navy, and Banana Republic online stores across 300+ repos, cutting open critical findings in the PCI DSS scope from 1,900 to 420.
- Rolled out HashiCorp Vault for 85 e-commerce and store apps, replacing passwords in Jenkins credentials and config files with secrets that rotate every 90 days.
- Ran OWASP Top 10 labs for 400+ developers before peak season and mentored 3 junior engineers through their first pipeline security changes.