Security Engineer

Quantum Technologies. LLC; Sunnyvale (CA); On-site; USD 140,000 - 210,000; Full time

Job summary

Quantum Technologies. LLC is seeking a security-focused professional to conduct ERD security and privacy reviews, perform threat modeling, and assess AI agents across our systems. You will build automation to improve consistency, lead targeted penetration testing, and drive remediation with engineering teams.

The role requires hands-on security engineering experience, strong communication, and the ability to work independently while collaborating across security, privacy, and product teams.

Qualifications

• 5+ years of relevant professional experience, including 3+ years in security engineering or a related security role.
• Experience conducting security design reviews, threat modeling, and privacy risk assessments.
• Hands-on penetration testing experience and a strong understanding of application, API, cloud, and data security.
• Software development or scripting experience with the ability to build tools and automate security workflows.
• Familiarity with AI agent architectures and risks involving prompt injection, tool execution, permissions, and data access.
• Strong written and verbal communication skills, including the ability to explain risks and recommend practical mitigations.
• Ability to work independently with minimal supervision and collaborate across engineering, security, and privacy teams.
• Bachelor’s or master’s degree in computer science, cybersecurity, or a related field, or equivalent practical experience.

Responsibilities

• Conduct ERD security and privacy reviews across applications, APIs, cloud infrastructure, and AI systems.
• Perform threat modeling to identify abuse cases and mitigation strategies.
• Assess and test AI agents, including prompt injection, data access, and external integrations.
• Build security automation to streamline ERD reviews, threat modeling, and testing workflows.
• Conduct targeted penetration testing of services, applications, APIs, and AI agents.
• Drive remediation and share knowledge with teams to prevent recurring security issues.

Skills

Security engineering

Threat modeling

Penetration testing

Software development

AI agent architectures

Technical communication

Independent work

Data security

Education

Bachelor's or Master’s in CS/Cybersecurity or related

Job description

What you’ll do:

• Conduct ERD security and privacy reviews: Evaluate engineering proposals, architecture, and data flows across applications, APIs, cloud infrastructure, and AI systems. Identify risks involving authentication, authorization, sensitive data handling, data minimization, retention, and third-party sharing.
• Perform threat modeling: Identify potential abuse cases and attack paths, recommend mitigations, and work with engineering teams to address risks before deployment.
• Assess and test AI agents: Evaluate third-party and internally developed coding and work-focused agents through adversarial testing. Examine prompt injection, tool use, permissions, data access, sensitive data exposure, and external integrations.
• Build security automation: Develop tools and AI-assisted workflows to streamline ERD reviews, threat modeling, evidence collection, and security testing, increasing assessment coverage and consistency.
• Conduct targeted penetration testing: Validate security assumptions and identify exploitable vulnerabilities in critical services, applications, APIs, and AI agents.
• Drive remediation and share knowledge: Communicate actionable findings, validate fixes, and develop guidance that helps teams prevent recurring security and privacy issues.

Required qualifications:

• 5+ years of relevant professional experience, including 3+ years in security engineering or a related security role.
• Experience conducting security design reviews, threat modeling, and privacy risk assessments.
• Hands-on penetration testing experience and a strong understanding of application, API, cloud, and data security.
• Software development or scripting experience, with the ability to build tools and automate security workflows.
• Familiarity with AI agent architectures and risks involving prompt injection, tool execution, permissions, and data access.
• Strong written and verbal communication skills, including the ability to explain risks and recommend practical mitigations.
• Ability to work independently with minimal supervision and collaborate across engineering, security, and privacy teams.
• Bachelors or master’s degree in computer science, cybersecurity, or a related field, or equivalent practical experience.

Preferred qualifications:

• Experience assessing AI agents, LLM applications, or third-party AI platforms.
• Experience building AI-powered security review or testing automation.
• Experience evaluating vendor security readiness and handling sensitive or business-critical data.
• Relevant security certifications, such as OSCP or CISSP.
• A passion for learning, teaching, and improving security practices.

We are an equal opportunity employer. All aspects of employment including the decision to hire, promote, discipline, or discharge, will be based on merit, competence, performance, and business needs. We do not discriminate on the basis of race, color, religion, marital status, age, national origin, ancestry, physical or mental disability, medical condition, pregnancy, genetic information, gender, sexual orientation, gender identity or expression, national origin, citizenship/ immigration status, veteran status, or any other status protected under federal, state, or local law.