Security Engineer

About the role

About StackOne

StackOne is the integration infrastructure for AI agents. Backed by GV and Workday Ventures ($24M raised), we make it possible for any AI agent — whether our customers build it into their product or buy it off the shelf — to take real action across the enterprise stack. Our platform gives agents 630+ connectors and 43,000+ pre-built actions, an AI connector builder for everything not covered yet, and the production layer agents actually need: semantic tool discovery that cuts token use by up to 80%, managed authentication and per-action permissions, the most accurate prompt injection defense on the market, and end-to-end observability.

Join us on our fast trajectory to build the future of agentic integrations.

ABOUT THE ROLE

We’re looking for a Security Engineer to be a key hire on our Engineering team and own our cloud and product security posture as we scale. You’ll work across our AWS and Cloudflare estate, harden our secure SDLC, run pen testing efforts end-to-end, and threat-model the features powering our connectors, OAuth flows, and agent execution paths.

It’s a hands-on, DevSecOps-heavy role: you write code, ship tooling, and embed security into how engineers work every day. You’ll report directly to the CTO and have broad scope across the platform (from CI/CD pipelines to multi-tenant APIs to incident response on authentication flows).

RESPONSIBILITIES

- Own the secure SDLC: drive SAST, dependency scanning, secrets detection, and PR-blocking standards across every repository.

- Harden our AWS and Cloudflare estate: IAM, secrets, network segmentation, KMS, WAF, GuardDuty, and zero-trust patterns.

- Run pen testing end-to-end: scope and coordinate engagements with both AI-driven scanners and human researchers, then drive findings through fix and retest.

- Threat-model product features before they ship, new Auth provider, expanded multi-tenant APIs, connector executions, agent tool-calling paths etc.

- Build detection and response capability around credential and authentication flows, with observability that closes incidents fast.

- Partner with engineering to raise the bar day-to-day: architecture reviews, written standards, and security embedded in code review.

- Use LLMs and agents to accelerate security workflows (triage, code review, evidence gathering) with guardrails you trust and help secure and monitor the (code/application/device) fleet.

- Support compliance work where it intersects security engineering: SOC 2, ISO 27001, customer security reviews, and pen test responses.

WHAT WE’RE LOOKING FOR

- 3+ years in security engineering with hands-on AWS security: IAM, KMS, networking, secrets, GuardDuty / Security Hub.

- Strong coding ability in TypeScript or Python or Go comfortable shipping production code, not just configs and scripts.

- Application security fluency: OWASP Top 10, threat modeling, and code-level reviews on real systems.