Platform Security Engineer Jobs in California (NOW HIRING)

As the platform security engineer, you'll help shape Applied Compute's security posture as we scale. We train custom models on the most sensitive thing our F500 customers have — their proprietary workflows, institutional knowledge, and production data — and we deploy autonomous agents back into those environments. Our customers rely on us being uncompromising about how we handle their data, credentials, and execution boundaries. We've built strong foundations to earn that trust and we're investing heavily in the people and systems to take it to the next level.

This role demands a security practitioner who thinks like an attacker, builds like an engineer, and has the judgment to know where to invest. You'll partner closely with infrastructure, product, and applied research engineers to make security a first-class concern from design through deployment. You'll also help us pioneer what AI-native defense looks like — using our own agent stack to detect, investigate, and pre-empt threats at machine speed. We're building security to defend against the strongest attackers with access to the most capable LLMs.

What you'll do

• Shape the security architecture of our platform end-to-end, from data and credential handling to agent execution and customer deployments
• Lead threat modeling and secure design reviews; identify and prioritize the risks, attack surfaces, and assumptions that matter most
• Drive our offensive security program: continuously stress-test our platform, agents, and pipelines against the kinds of adversaries we should actually expect to face
• Build the tooling, automation, and detections that scale security across the company — including agent-based systems that turn our AI capabilities into a defensive force multiplier
• Partner with engineers across the company to instill secure-by-default practices and remove classes of risk through better design
• Own the security guarantees we present to enterprise customers and their CISOs
• Lead incident response when it matters: detection, containment, communication, and durable fixes
• Build our security teams as we grow

What we're looking for

• 5+ years of hands-on experience in platform security and cyber defense
• Have an exceptional eye for finding flaws others miss, and instinctively ask "how would I break this"
• Lead with a strong grasp of offensive security, anticipating risk from an adversary's perspective rather than checking compliance boxes
• Bring a builder's mindset — you have experience shipping secure software to production
• Have strong judgment to identify the most important security vulnerabilities and put into practice
• Reduce risk through secure design and simplicity; advocate for fundamentals like least privilege, defense-in-depth, and minimizing complexity
• Are energized by ambiguity and high autonomy

Strong candidates also have

• Hands-on experience securing complex cloud and multi-tenant environments, especially ones deployed inside customer VPCs
• Familiarity with AI/agent-specific risks: prompt injection, tool use abuse, data and model exfiltration
• Background in offensive security, vulnerability research, or red teaming against cloud or AI systems
• Experience using LLMs to accelerate security workflows — detection, investigation, triage, or automated response
• Track record taking compliance programs (SOC 2, ISO 27001, HIPAA, FedRAMP) to completion as engineering efforts
• Previous experience as a founder, security lead, or early engineer at a zero-to-one company

Applied Compute builds Specific Intelligence for the enterprise. We provide the continual learning infrastructure for companies to build agent workforces trained on proprietary data and institutional expertise. Our researchers and platform embed directly within customer environments to build custom evals, train models, and deploy agents that get better with use.

• Why we're excited: We get to work at a rare intersection. Our product team builds the platform powering a new generation of digital coworkers. Our research team pushes the frontier of post-training and reinforcement learning. Our applied AI team sits side-by-side with customers as they ship agents into production. This combination of strong product, deep research, and boots on the ground is what we believe it takes to bring AI to the enterprise. We are product-led, research-enabled, and forward-deployed.

• Who we are: We're a team of engineers, researchers, and operators. Many of us are former founders. We've built RL infrastructure at OpenAI, data foundations at Scale AI, and systems at Together, Two Sigma, Watershed, and others. We work with F50 customers and are fortunate to be backed by partners like Kleiner Perkins, Benchmark, Sequoia, Lux, and Greenoaks.

• Who Thrives Here: We're looking for people who are excited about applying novel research and complex systems to real-world problems. Our team genuinely enjoys working with customers: listening, empathizing, and understanding how work actually gets done in their organizations. Former founders, people who've built a lot of side projects, or anyone who's shown they can own something end-to-end, tend to do well here.

This role is based in San Francisco. We work from our office in the Mission. We offer:

• Competitive compensation and equity
• Generous health benefits
• Unlimited PTO
• Paid parental leave
• Daily lunches and dinners
• Transportation and relocation support
• Retirement plans

We sponsor visas. While we can't guarantee success for every candidate or role, if you're the right fit, we're committed to working through the process with you. We encourage you to apply even if you do not believe you meet every single qualification. As set forth in Applied Compute's Equal Employment Opportunity policy, we do not discriminate on the basis of any protected group status under any applicable law.