Responsibilities
- Own the secure SDLC, including SAST, dependency scanning, secrets detection, and pull-request blocking standards across repositories.
- Harden the AWS and Cloudflare environments through IAM, secrets management, network segmentation, KMS, WAF, GuardDuty, and zero-trust patterns.
- Run penetration-testing engagements end to end, coordinating AI-driven scanners and human researchers and driving findings through remediation and retesting.
- Threat-model new product features, authentication providers, multi-tenant APIs, connector executions, and agent tool-calling paths.
- Build detection, response, and observability capabilities for credential and authentication flows.
- Partner with engineering on architecture reviews, written security standards, and security-focused code reviews.
- Use LLMs and agents to accelerate security workflows with appropriate guardrails, while helping secure and monitor the code, application, and device fleet.
- Support security-related compliance work involving SOC 2, ISO 27001, customer security reviews, and penetration-test responses.
Requirements
- At least 3 years of security engineering experience with hands-on AWS security, including IAM, KMS, networking, secrets, GuardDuty, or Security Hub.
- Strong production coding ability in TypeScript, Python, or Go.
- Application-security fluency covering the OWASP Top 10, threat modeling, and code-level reviews.
- Experience securing a B2B SaaS multi-tenant production environment.
- Ability to own end-to-end work from scoping through delivery and measurement.
- Clear communication with engineering, product, and non-technical stakeholders.
- Preference for automating security checks rather than relying on manual checklists.
- Preferred: fluency with AWS CDK or Terraform and ability to review infrastructure code and write custom scanning rules.
- Preferred: experience with Aikido, Drata, Cloudflare Workers, or penetration testing in a compliance-mature environment.
Benefits
- Meaningful EMI share options.
- 25 days of holiday plus one additional day per year of tenure.
- Private health insurance including dental and optical coverage.
- £15 per day lunch budget when working from the London office, up to £120 per month.
- £1,000 home-office setup allowance plus a £500 annual top-up.
- Annual team offsite.
- Health, fitness, and gift-card discounts.
- Cycle2Work and Electric Cars scheme.
- Hybrid working, typically two days per week in the London office, with flexible arrangements open for discussion.
About StackOne
StackOne is the integration infrastructure for AI agents to act. 200+ connectors, 10k+ actions, and the AI builder tools to customize or build your own. StackOne turns AI agents into powerhouse that can act like your and for you. At the core is Falcon, our state-of-the-art, code-first, execution engine. Falcon executes multi-step AI actions accurately, reliably, and securely, optimizing for tool-calling accuracy, token efficiency, and low latency. Falcon interfaces with your agent via MCP, A2A, or API calls for traditional apps RPCs and any app interface (REST, SOAP, GraphQL, Private APIs, browserless). StackOne’s managed infrastructure handles multi-tenant authentication, permissions, and observability out of the box—so teams can focus on designing agency, not building the plumbing. We’re built for enterprise trust: SOC2, GDPR, HIPAA, and CCPA compliant. Real-time execution with no data storage. Ship faster. Execute better. Scale with confidence. StackOne is the platform for production-ready autonomous agents.