Security Engineer

📋 Job Overview

Simile is The Simulation Company. We simulate human behavior to keep people at the center of the decisions that shape the world. With AI, anyone can create a product, a campaign, a policy, or a script — the bottleneck has moved upstream. The hard question is no longer whether you can create something, but what to create, for whom, and how to bring it to life. Those are fundamentally human decisions, and they shouldn't be left to chance or handed off to an algorithm. We're building the infrastructure to understand human behavior at scale and to represent humans in an increasingly agentic world. Our mission is to simulate all eight billion people on earth.

🏢 About Simile

We launched five months ago. Since then we've grown revenue 5x, built a new foundation model for human behavior that has run tens of millions of simulations for F100 enterprises, trained a first-of-its-kind confidence model that predicts the accuracy of every simulation, and released the first product that lets organizations verifiably predict the future. The world's leading companies use Simile to make business-critical decisions — from consumer leaders like CVS Health and Wealthfront to professional services organizations like Deloitte and Gallup — strategizing product launches, entering new markets, and forecasting earnings calls.

We've raised over $200M at a $2B post-money valuation led by Greenoaks, with Index Ventures, Hanabi, A*, Bain Capital Ventures, and CVS Health Ventures. We've grown from a small home in Palo Alto to a global team of 50+, and we're building a team of the best researchers, engineers, designers, and operators in the world. The future is too important to be left to chance.

🎯 The Role

We are looking for a Security Engineer who thrives on securing novel AI products. You will own the security roadmap, ensuring our platform is resilient, compliant, and stays ahead of an ever-evolving threat landscape.

✅ Key Responsibilities

• Customer Security & Trust: Partner with our largest enterprise customers to navigate the procurement process, leading technical discussions regarding security agreements, providing comprehensive posture overviews, and ensuring alignment on rigorous data handling requirements
• Lead Secure Design: Conduct threat modeling and secure design reviews for new features, ensuring security is a core consideration from initial design through implementation.
• Automate Defenses: Develop tooling and \"paved paths\" that allow our engineering and research teams to ship code safely without sacrificing velocity.
• Own Vulnerability Management: Oversee our bug bounty program and internal vulnerability scanning, prioritizing fixes based on actual risk to our foundation models.
• Secure AI/ML Pipelines: Build specific defenses against AI-novel risks, including protecting high-throughput inference systems and GPU-accelerated computing environments.
• Champion GitOps Security: Manage security configurations via Terraform/Pulumi, ensuring \"security-as-code\" is the truth across all multi-region environments.

📌 Required Qualifications

• Experience: 5+ years of experience in application or infrastructure security within a high-growth environment.
• Security Polyglot: Deep expertise in securing AWS environments; experience with GCP or Azure is a major plus.
• Offensive Mindset: Ability to think like an attacker to anticipate risks, paired with a collaborative spirit to help engineers remediate them.
• Operational Mindset: Experience with modern observability and a \"you build it, you run it\" mentality toward security infrastructure.
• Agentic Security Tooling: Experience integrating agentic AI workflows into the developer lifecycle to provide real-time security feedback, enabling engineers to be \"secure-by-design\" as code is written rather than after the fact.

⭐ Desirable Experience

• AI/ML Security: Experience securing AI/ML workloads, specifically defending against prompt injection or protecting model weights.
• Kubernetes Mastery: Strong K8s (EKS/GKE) experience, specifically around multi-tenant security and resource isolation.
• Compliance Expertise: Proven track record of navigating SOC2, HIPAA, or similar regulatory frameworks in a cloud-native environment.

🎁 Benefits

At Simile, we provide competitive compensation packages that include base salary, equity, and comprehensive benefits.

Salary Range: $200,000 – $400,000 USD

Note: Final offers are based on experience, specialized skills, interview performance, and relevant training.

Equity: Grants are available for eligible roles, subject to board approval.

Health & Wellness: Comprehensive medical, dental, and vision coverage.

Time Off: Flexible time off policies to support work-life balance.

🛂 Visa & Eligibility

Reapplication Policy: To ensure a fair and thorough evaluation for all applicants, Simile