Senior AppSec Engineer: Build Secure, Scalable Tools

The Trade Desk; Bellevue (NY); On-site; USD 113,500 - 208,100; Full time

Job summary

The Trade Desk is seeking a Senior Application Security Engineer to strengthen our Cybersecurity Department. You will own and extend scalable AppSec tooling, lead threat modeling, and harden our platform used by leading brands worldwide.

This role emphasizes hands-on engineering, secure-by-design practices, and collaboration with cross-functional teams to reduce risk. You will also review new features, conduct security-focused code reviews, and help secure AI/ML systems, while driving governance

Qualifications

• BS degree or equivalent years of experience in a related field.
• 6+ years in application security with tooling and automation.
• Hands-on coding experience in at least one language (C#, Java, Python, Go or JS).
• Experience with SAST, DAST, SCA, and secrets management tooling.
• Practical threat modeling experience (STRIDE, PASTA, or equivalent).
• Experience with vulnerability management workflows at scale.
• Knowledge of Kubernetes and container security; cloud fundamentals.
• Experience in AI/ML security or GenAI-related security tooling is a plus.

Responsibilities

• Extend and own scalable AppSec tooling across core areas.
• Triage, reproduce, and contextualize scanner findings for engineers.
• Review features and API changes; conduct secure code reviews and tests.
• Write production-quality security automation and tooling.
• Assess AI/ML systems including inference APIs and GenAI surfaces.
• Drive security culture with direct engineering partnership.
• Develop and publish standards, guidelines, and secure baselines.

Skills

SAST/DAST/DAST tooling

Threat modeling

Security tooling automation

CI/CD integration

Kubernetes security

Cloud security (AWS/GCP/Azure)

AI/ML security

Code review (C#, Java, Python, Go, JS)

Strong communication

OSWE/GWAPT/CSSLP/OSCP or equivalents

Education

BS degree or equivalent

Tools

GitHub Actions

GitLab

Jenkins

ArgoCD

SAST/DAST tools

Job description

The Trade Desk is seeking a Senior Application Security Engineer to strengthen our Cybersecurity Department. You will own and extend scalable AppSec tooling, lead threat modeling, and harden our platform used by leading brands worldwide.

This role emphasizes hands-on engineering, secure-by-design practices, and collaboration with cross-functional teams to reduce risk. You will also review new features, conduct security-focused code reviews, and help secure AI/ML systems, while driving governance