We are a product team within Leadtech's AI-LAB. Our job is to research, prototype, develop, launch and scale challenging AI products across the Leadtech portfolio.
We're looking for a Senior AI Frontend Engineer who can launch a product and scale it: someone with experience in UX/UI design, A/B testing and product metrics, and who incorporates AI-native tools by default.
This is a frontend-first role with full-stack reach.
Turn a concept into something users can click within days, put it in front of them, and double down or discard it based on what you learn.
Once a product finds traction, you'll grow it: hardening the codebase for a larger user base, keeping performance and quality high as scope expands, and evolving features based on how real users behave.
Own the frontend : architecture, component library, design system, and the UX that make a great product.
Proactively instrument features, run experiments, read the funnel data, and iterate based on what you discover. 5+ years of frontend engineering, with deep TypeScript and React proficiency (Hooks, Context API,



state management, Vite, Tailwind, Shadcn UI) and a track record of owning significant surface area.
~ You can distinguish between good and bad UX, articulate why, and share examples from your own work to demonstrate it. You're comfortable in Figma and you hold opinions on typography, spacing and motion.
~ Design systems and component APIs built to last, responsive and mobile-first layouts, accessibility and frontend performance work across bundle size.
~ You've run or interpreted A/B tests and can distinguish a real result from noise.
~ Solid backend foundations . Node.js, Express, REST APIs and PostgreSQL. You can build the endpoint you need rather than wait for it.
~ Hands-on SEO experience: technical audits, SSR/SSG rendering strategy (Next.js), structured data, international and multi-market pages.
Familiarity with experimentation and analytics tooling (Amplitude, GA4).
Experience with LLM engineeri

📌 Senior Front End Developer (España)
🏢 Leadtech
📍 España