As the first dedicated Security Engineer at StackOne, you will own the cloud and product security posture end-to-end. Reporting to the CTO, you will build security tooling in TypeScript/Python, harden AWS/Cloudflare infrastructure, and threat-model features handling complex OAuth flows. You’ll enable engineers by automating security directly into the SDLC.
Security Engineer at StackOne
This is a high-impact, builder-centric role where you'll own cloud and product security end-to-end, reporting directly to the CTO. From hardening AWS infrastructure to building custom security tooling in TypeScript and Python, you'll shape the security architecture for a platform powering thousands of enterprise integrations. If you're a hands-on engineer looking to define the security standards of a fast-growing London startup and work with a senior team of veterans from Google and Microsoft, this is your opportunity to build the future of agentic integrations.
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Location
London, United Kingdom
Compensation
£70k-£110k + Equity
Company
StackOne
Role overview
SoftwareCanterbury, United KingdomSeries A (VC-backed)
StackOne is the AI Integration Gateway for SaaS products and AI Agents. With operations in the UK and US, the company enables builders of SaaS platforms and AI Agents to orchestrate hundreds of scalable, accurate, and enterprise-grade integrations. Their 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. The company was founded by a team of former Google, Oracle, JP Morgan, Coinbase, and Microsoft employees with a mission to build the most advanced integration infrastructure for generative AI applications. StackOne has experienced rapid growth, serving enterprise clients globally, and is backed by notable investors, including GV (Google Ventures), Workday Ventures, and Episode 1.
Backed by GV (Google Ventures), Workday Ventures, XTX Ventures, Episode 1 Ventures, Playfair Capital, Founders of GitHub, Founders of Onfido, Founders of Hofy, Angel investors from OpenAI, Angel investors from Google DeepMind, Angel investors from Microsoft, Angel investors from MuleSoft.
What you will do
- Own the secure SDLC by driving SAST, dependency scanning, and secrets detection standards across all repositories and CI/CD pipelines.
- Harden the AWS and Cloudflare estate using zero-trust patterns, network segmentation, and advanced IAM/KMS configurations for multi-tenant environments.
- Threat-model new product features, connector executions, and agent tool-calling paths to ensure robust security for complex authentication and OAuth flows.
Who this is a fit for
- 3+ years of security engineering experience with deep hands-on expertise in AWS security services like GuardDuty, Security Hub, and KMS.
- Proficiency in shipping production-grade code using TypeScript, Python, or Go, with a strong background in Infrastructure as Code (CDK or Terraform).
- Solid understanding of application security, including OWASP Top 10, threat modeling, and securing B2B SaaS multi-tenant environments at scale.
Why this role is remarkable
- First security hire opportunity: Define the security architecture and strategy from the ground up for a high-growth AI infrastructure startup.
- High-caliber backing: Supported by top-tier investors like GV and Workday Ventures with $24M raised to scale the future of agentic integrations.
- Builder-centric culture: This is a hands-on DevSecOps role where you ship production code and tooling rather than just managing GRC checklists.
How Jack & Jill work together
I get to know what you’re great at, then find roles you’d never find yourself.Ok, I'll go first. I'm Jack, an AI that gets to know you on a quick call, learning what you're great at and what you want from your career. Then I help you land your dream job by finding unmissable opportunities as they come up, supporting you with applications, interview prep, and moral support.
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