Senior AI Security Engineer II — Threat Modeling & Controls

Hi Marley; Boston (MA); Hybrid; USD 121,000 - 226,000; Full time

Benefits offered by this job

Equity grants for all employees

4% 401(k) matching

Health, dental, vision, disability, &‑

Monthly wellness stipend

Parental leave

Flexible vacation policy

Job summary

Hi Marley is seeking a Senior Security Engineer II to secure our AI across the company, focusing on internal AI environments, tools, agents, and MCP connectors. You’ll threat-model new capabilities, perform adversarial testing, and ensure governance with auditors and leadership.

This role requires hands-on security work and collaboration across teams in a hybrid Boston office setting. You will join a security-first culture that values practical AI risk management, strong Python tooling, and AWS

Qualifications

• 5+ years in security engineering, application security, or infrastructure security with hands-on AI/ML exposure.
• Experience securing or building LLM-based systems, agent frameworks, or ML pipelines in cloud environments.
• Strong knowledge of AI-specific attack surfaces: prompt injection, data leakage, privilege escalation.
• Hands-on familiarity with how AI systems actually work.
• Strong proficiency in Python and security tooling, automation, and testing.
• Strong working knowledge of AWS security, IAM, networking, encryption, and monitoring.

Responsibilities

• Apply AI security design patterns to LLM integrations, agent frameworks, MCP connectors, and data pipelines.
• Lead threat modeling for new AI capabilities and drive mitigations.
• Enforce controls for agent isolation, least-privilege execution, credential scoping, and data boundaries.
• Maintain inventory of AI tools and data flows, access controls, and permissions.
• Run AI risk assessments and manage red-teaming and remediation cadence.
• Operate agent and MCP lifecycle from proposal to retirement.

Skills

Python

AWS security

Threat modeling

LLM security

Vulnerability assessment

Security tooling

Tools

MCP connectors

Agent orchestration

DLP/Observability tools

Job description

Hi Marley is seeking a Senior Security Engineer II to secure our AI across the company, focusing on internal AI environments, tools, agents, and MCP connectors. You’ll threat-model new capabilities, perform adversarial testing, and ensure governance with auditors and leadership.

This role requires hands-on security work and collaboration across teams in a hybrid Boston office setting. You will join a security-first culture that values practical AI risk management, strong Python tooling, and AWS