Security Engineer

San Francisco March 7, 2026 Full Time

About the Role

You'll be the first security engineer at a company processing millions of sensitive data points across AI training pipelines, expert payments, and enterprise integrations. This is not a monitoring role. You'll build the systems that keep Mercor secure - writing detection logic, automating response workflows, hardening infrastructure, and shipping security tooling that scales with a company growing faster than most teams can keep up with.

We use AI heavily in our own security work. You should be comfortable building alongside AI code-gen tools, using LLMs to accelerate threat analysis, and automating away the repetitive work that slows security teams down. If you're the kind of engineer who writes a script instead of filing a ticket, you'll fit in here.

We're in-person five days a week at our SF headquarters, with first Fridays remote.

What You'll Build:

  • Detection and response pipelines that catch real threats, not checkbox alerts

  • Security automation that replaces manual processes - if you're doing something twice, automate it

  • Infrastructure hardening across AWS, Kubernetes, and our production environment

  • Identity and access controls for a platform serving 300K+ experts and enterprise clients

  • Application security tooling integrated into CI/CD - shifting security left without slowing down deploys

  • Incident response runbooks and tooling - when something breaks, you'll own the fix end-to-end

What We're Looking For

  • You've built security tooling or automation in a previous role - not just operated existing tools

  • Strong in Python, Go, or TypeScript - you ship code, not slide decks

  • Experience hardening cloud infrastructure (AWS preferred) - VPCs, IAM, container security

  • You understand application security at the code level - can review a PR for auth bugs, not just run a scanner

  • Comfortable with detection engineering - writing rules, tuning alerts, reducing noise

  • You've done incident response and know what it means to be on-call when things break

  • 5+ years of professional experience in security engineering, software engineering, or a related builder role

Bonus Points

  • Experience at a high-growth startup or fast-moving engineering org

  • Familiarity with AI/ML security - model access controls, training data protection, prompt injection

  • Offensive security skills - pen testing, bug bounty, red team experience

  • Contributions to open source security tools

  • You've built something from scratch that a team still uses

Why Mercor

  • Build, don't babysit. We automate the boring stuff. You'll spend your time building systems, not reviewing access requests.

  • AI-native security. You'll use frontier AI tools daily - for code review, threat analysis, detection writing, and anything that benefits from an AI co-pilot.

  • Ownership from day one. Small team, massive surface area. You'll own entire security domains, not a single dashboard.

  • See the future early. Working alongside AI labs means you'll understand frontier model capabilities months before the market.

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