StackOne Technologies Limited
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. Why this role exists StackOne's product experience is our brand. As our first dedicated UX Engineer you will be the in-house authority on taste, polish, and performance. You will own the component library, shape our micro-frontend architecture, and ensure that every pixel, motion, and millisecond of latency makes customers feel like they're using the best-engineered platform on the market. What you'll do 80 % Front-end craft & design systems 20 % API-aware performance engineering Collaborate with our Designer to define & steward our design system - set the visual language, build reusable primitives, and maintain libraries that power every StackOne user interfaces. Ship pixel-perfect UIs - React (primarily) plus; own theming, performance, and thoughtful motion. Make performance a feature - instrument Core Web Vitals, budget bundle sizes, optimise hydration patterns, and chase performance where it matters. Provide and maintain internal tooling as well as AI rules to allow every technical team to contribute to the front-end while aligning with the best practices you will help set. Prototype & validate - turn product ideas into interactive proofs-of-concept that help PMs and designers converge on the right solution fast. Champion taste & detail - host design-quality critiques, stamp out visual debt, and be the go-to voice when "good enough" isn't. What you'll bring Must-haves 4+ yrs professional front-end engineering with a portfolio that focus on the details. React & TypeScript at production scale; comfortable with hooks, suspense, and server components. Deep CSS fluency (Tailwind or equivalent) and experience of modern browser APIs. Proven track record building or migrating component libraries/design systems. Strong performance tuning instincts: Lighthouse, Core Web Vitals, bundle analysis, code-splitting. Familiarity with monorepo tooling (NX or Turborepo) and micro-frontend patterns. Ability to dive into back-end code (Node, React-router, sveltekit) to remove perf bottlenecks, instrument metrics, or adjust API shape. Nice-to-haves Svelte, Web Components, or other framework experimentation. Experience with auth flows (OAuth2, OpenID Connect) and secure front-end patterns. Web Motion & animation chops Prior work on B2B developer tools or dashboards at seed-to-Series-B stage. Why Join Us? Meaningful share options (EMI) - share in the company's success as we grow 25 days holiday + 1 additional day per year of tenure Private health insurance - including dental & optical £15/day lunch budget when working from our London office, up to £120/month £1,000 for your home office set up + £500/year top-up Annual team offsite to sunny spots (last ones were in Spain and Portugal) Join one of Europe's fastest-growing startups Work with a veteran team of ex-employees of Google, Microsoft, Oracle, Coinbase, JP Morgan and more Health, fitness and gift card discounts Cycle2Work and Electric Cars scheme Hybrid work set up - typically 2 days in the office We believe diversity drives innovation. We encourage individuals from all backgrounds to apply. As an equal-opportunity employer, we celebrate diversity and are committed to creating an inclusive environment for all employees.
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. Why this role exists StackOne's product experience is our brand. As our first dedicated UX Engineer you will be the in-house authority on taste, polish, and performance. You will own the component library, shape our micro-frontend architecture, and ensure that every pixel, motion, and millisecond of latency makes customers feel like they're using the best-engineered platform on the market. What you'll do 80 % Front-end craft & design systems 20 % API-aware performance engineering Collaborate with our Designer to define & steward our design system - set the visual language, build reusable primitives, and maintain libraries that power every StackOne user interfaces. Ship pixel-perfect UIs - React (primarily) plus; own theming, performance, and thoughtful motion. Make performance a feature - instrument Core Web Vitals, budget bundle sizes, optimise hydration patterns, and chase performance where it matters. Provide and maintain internal tooling as well as AI rules to allow every technical team to contribute to the front-end while aligning with the best practices you will help set. Prototype & validate - turn product ideas into interactive proofs-of-concept that help PMs and designers converge on the right solution fast. Champion taste & detail - host design-quality critiques, stamp out visual debt, and be the go-to voice when "good enough" isn't. What you'll bring Must-haves 4+ yrs professional front-end engineering with a portfolio that focus on the details. React & TypeScript at production scale; comfortable with hooks, suspense, and server components. Deep CSS fluency (Tailwind or equivalent) and experience of modern browser APIs. Proven track record building or migrating component libraries/design systems. Strong performance tuning instincts: Lighthouse, Core Web Vitals, bundle analysis, code-splitting. Familiarity with monorepo tooling (NX or Turborepo) and micro-frontend patterns. Ability to dive into back-end code (Node, React-router, sveltekit) to remove perf bottlenecks, instrument metrics, or adjust API shape. Nice-to-haves Svelte, Web Components, or other framework experimentation. Experience with auth flows (OAuth2, OpenID Connect) and secure front-end patterns. Web Motion & animation chops Prior work on B2B developer tools or dashboards at seed-to-Series-B stage. Why Join Us? Meaningful share options (EMI) - share in the company's success as we grow 25 days holiday + 1 additional day per year of tenure Private health insurance - including dental & optical £15/day lunch budget when working from our London office, up to £120/month £1,000 for your home office set up + £500/year top-up Annual team offsite to sunny spots (last ones were in Spain and Portugal) Join one of Europe's fastest-growing startups Work with a veteran team of ex-employees of Google, Microsoft, Oracle, Coinbase, JP Morgan and more Health, fitness and gift card discounts Cycle2Work and Electric Cars scheme Hybrid work set up - typically 2 days in the office We believe diversity drives innovation. We encourage individuals from all backgrounds to apply. As an equal-opportunity employer, we celebrate diversity and are committed to creating an inclusive environment for all employees.
StackOne Technologies Limited
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 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. 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. Clear communication with engineers, product, and non technical stakeholders. Bias toward automating security checks instead of running manual checklists. (Preferred) IaC fluency in AWS CDK or Terraform, comfortable reviewing infrastructure code for security misconfigs and writing custom scanning rules. (Preferred) Experience with Aikido, Drata, Cloudflare Workers, or pen testing in a compliance mature environment. Our Stack We're pragmatic about tooling. Today's stack includes: Cloud & infra: AWS (ECS, RDS, Lambda, KMS, GuardDuty, Security Hub, Inspector), Cloudflare (Workers, WAF, Zero Trust) IaC: AWS CDK, Terraform Security tooling: Aikido (SAST, DAST, container scanning, pen testing), 1Password, GitHub (org level enforcement, Advanced Security) Compliance & ops: Drata, Iru, EasyLlama Observability & IR: Datadog, Sentry, Logfire, Incident.io Languages: TypeScript (Node.js), Python Benefits Meaningful share options (EMI) - share in the company's success as we grow 25 days holiday + 1 additional day per year of tenure Private health insurance - including dental & optical £15/day lunch budget when working from our London office, up to £120/month £1,000 for your home office set up + £500/year top up Annual team offsite to sunny spots (last ones were in Spain and Portugal) Join one of Europe's fastest-growing startups Work with a veteran team of ex employees of Google, Microsoft, Oracle, Coinbase, JP Morgan and more Health, fitness and gift card discounts Cycle2Work and Electric Cars scheme Hybrid working friendly - typically 2 days/week in our London office. We're open to discussing flexible arrangements-please share any preferences in your application We believe diversity drives innovation. We encourage individuals from all backgrounds to apply. As an equal opportunity employer, we celebrate diversity and are committed to creating an inclusive environment for all employees.
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 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. 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. Clear communication with engineers, product, and non technical stakeholders. Bias toward automating security checks instead of running manual checklists. (Preferred) IaC fluency in AWS CDK or Terraform, comfortable reviewing infrastructure code for security misconfigs and writing custom scanning rules. (Preferred) Experience with Aikido, Drata, Cloudflare Workers, or pen testing in a compliance mature environment. Our Stack We're pragmatic about tooling. Today's stack includes: Cloud & infra: AWS (ECS, RDS, Lambda, KMS, GuardDuty, Security Hub, Inspector), Cloudflare (Workers, WAF, Zero Trust) IaC: AWS CDK, Terraform Security tooling: Aikido (SAST, DAST, container scanning, pen testing), 1Password, GitHub (org level enforcement, Advanced Security) Compliance & ops: Drata, Iru, EasyLlama Observability & IR: Datadog, Sentry, Logfire, Incident.io Languages: TypeScript (Node.js), Python Benefits Meaningful share options (EMI) - share in the company's success as we grow 25 days holiday + 1 additional day per year of tenure Private health insurance - including dental & optical £15/day lunch budget when working from our London office, up to £120/month £1,000 for your home office set up + £500/year top up Annual team offsite to sunny spots (last ones were in Spain and Portugal) Join one of Europe's fastest-growing startups Work with a veteran team of ex employees of Google, Microsoft, Oracle, Coinbase, JP Morgan and more Health, fitness and gift card discounts Cycle2Work and Electric Cars scheme Hybrid working friendly - typically 2 days/week in our London office. We're open to discussing flexible arrangements-please share any preferences in your application We believe diversity drives innovation. We encourage individuals from all backgrounds to apply. As an equal opportunity employer, we celebrate diversity and are committed to creating an inclusive environment for all employees.