StackOne

AI Integration Gateway for SaaS products and AI Agents

SecurityEngineer

London, United Kingdom FULL TIME Remote Friendly
Market Sentiment
HIGH DEMAND

Neural analysis suggests this role is
optimal for Mid candidates.

The Brief

“Security Engineer at StackOne. Skills: cloud and product security posture, AWS and Cloudflare estate, secure SDLC, pen testing, threat-model, DevSecOps, code, tooling, CI/CD pipelines, multi-tenant APIs, incident response. 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.”

What You'll Achieve.

Own our cloud and product security posture as we scale; drive SAST, dependency scanning, secrets detection, and PR-blocking standards across every repository; Harden our AWS and Cloudflare estate; Run pen testing end-to-end; Threat-model the features powering our connectors, OAuth flows, and agent execution paths; Build detection and response capability around credential and authentication flows, with observability that closes incidents fast; raise the bar day-to-day; Use LLMs and agents to accelerate security workflows; Support compliance work

Industry & Context.

AI Integration Gateway for SaaS products and AI Agents

What They're Looking For.

Must Have

3+ years in security engineering with hands-on AWS security: IAM, KMS, networking, secrets, GuardDuty / Security Hub, 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, Experience securing a B2B SaaS multi-tenant production environment, Comfort owning end-to-end work: scope, ship, measure. You don’t wait for a queue.

Nice to Have

IaC fluency in AWS CDK or Terraform, comfortable reviewing infrastructure code for security misconfigs and writing custom scanning rules, Experience with Aikido, Drata, Cloudflare Workers, or pen testing in a compliance-mature environment

What You'll Do.

Own the secure SDLC: drive SAST

and PR-blocking standards across every repository.

Harden our AWS and Cloudflare estate: IAM

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

expanded multi-tenant APIs

agent tool-calling paths etc.

Build detection and response capability around credential and authentication flows

with observability that closes incidents fast.

Use LLMs and agents to accelerate security workflows (triage

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

customer security reviews

and pen test responses.

How You'll Work.

Team & Collaboration

Partner with engineering to raise the bar day-to-day: architecture reviews, written standards, and security embedded in code review.; Clear communication with engineers, product, and non-technical stakeholders.

Communication Scope

Clear communication with engineers, product, and non-technical stakeholders.

Process & Methodology

Comfort owning end-to-end work: scope, ship, measure. You don’t wait for a queue.

Full Job Description

About StackOne: StackOne is the AI Integration Gateway for SaaS products and AI Agents. Backed by GV and Workday Ventures ($24M raised), we help builders of SaaS platforms and AI Agents orchestrate hundreds of scalable, accurate, and enterprise-grade integrations. Our platform combines 25,000 pre-mapped actions on 200 connectors, an AI-powered integration development toolkit, plus security by design: a real-time architecture, managed authentication and permissions, 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 re

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