Job Details

Join the fastest-growing startup in history — and secure systems, infrastructure and data which powers the world's leading AI labs.

Title of Role: Security Engineer

Company Stage of Funding: Hyper-Growth, Highly Profitable Private Company

Office Type: On-site, Full-Time

Overview

About Mercor: As a top partner in the human data space, powering model training for the world's leading AI labs and tech companies. Mercor's platform makes LLM eval better and already drives hiring and decision-making for major AI labs and hyperscalers. In fact, Mercor grew from $1M to $500M in revenue run rate in just 17 months, making it the fastest-growing company in history.

What You Will Do

• As a Security Engineer, you'll safeguard core systems, infrastructure, and data while ensuring security is integrated seamlessly into development and deployment processes. You will:
• Design and implement security controls across infrastructure, applications, and networks.
• Monitor for vulnerabilities, threats, and suspicious activity.
• Conduct penetration tests, vulnerability assessments, and incident response.
• Embed security practices into CI/CD pipelines and developer workflows.
• Ensure compliance with frameworks (SOC 2, ISO 27001, GDPR).
• Partner with engineers to make security a first-class part of system design.
• Research and respond proactively to emerging threats.

Ideal Background

• Strong knowledge of security principles, tools, and best practices.
• Experience with SIEMs, IDS/IPS, firewalls, and vulnerability scanning.
• Familiarity with cloud security (AWS, GCP, or Azure).
• Solid understanding of encryption, authentication, and authorization systems.
• Track record of securing distributed, high-scale environments.
• Excellent collaboration and communication skills.
• Ability to balance security rigor with speed in a hyper-growth environment.

Why Join

• Impact: Own the security function that powers critical infrastructure for the world's leading AI labs.
• Learning: Gain early exposure to frontier AI systems and emerging risks.
• Growth: Take on both infrastructure and research-adjacent projects with fast paths to ownership.

Compensation and Benefits

• Equity: Generous early-stage equity package
• Work Setup: On-site in San Francisco

Other Benefits

• Direct ownership of security architecture and practices
• Chance to shape security culture in a hyper-growth engineering environment
• Work alongside senior engineers at the intersection of AI and infrastructure

This role is perfect for security engineers who want to build practical, scalable defenses in high-growth environments — balancing rigor with speed while safeguarding mission-critical AI infrastructure.