Founding Senior Frontend Engineer

Description

Job Summary: NAIIAN is seeking a Founding Senior Frontend Engineer to build the primary web experience for an AI-powered cloud platform, developing complex operational interfaces and serving as a key member of the first wave of engineering. Key Highlights: 1. True ownership of product experience and AI platform definition. 2. Direct collaboration with the CPO, CTO, and founding team. 3. Development of frontend architecture and operational UX. **Location:** Madrid (Preferably on-site, with high flexibility negotiable) **Compensation:** EUR 70,000–90,000 gross annually + significant founding equity + benefits https://jobs.ashbyhq.com/naiian/fdf78111\-2641\-4620\-a214\-7bcb1d949956 **About NAIIAN and the Challenge** NAIIAN is a well-funded European Deep Tech startup with its founding team based in Madrid. We are building an AI-powered cloud platform for clients operating in contexts demanding high operational and decision-making rigor. The interface will be central to the product: documents, evidence, verifiable sources, loading and processing states, maps, timelines, copilots, human approval, and decisions that must be clearly understood. We are looking for our **Founding Senior Frontend Engineer** to build NAIIAN’s primary web experience. This is not a role focused on static mockups or landing pages. It is a product frontend role: complex operational interfaces, real data, edge cases, performance, accessibility, and close collaboration with the CPO, design, backend, and AI teams. When the product moves beyond a demo, the frontend must not become a bottleneck. **Our Approach to Teamwork:** We firmly believe in the magic that happens when working side-by-side in front of a whiteboard during this critical 0-to-1 phase. Therefore, our ideal scenario is having you join us at our Madrid office. However, we recognize that exceptional talent requires flexibility. If you’re the right person, we’ll sit down together to design a work model—hybrid or concentrated on-site—that fits both your life and the company’s goals. **Why Join Us** * You’ll join NAIIAN’s first wave of engineering, with true ownership over the product experience. * You’ll define how a complex AI platform becomes understandable, useful, and trustworthy for real users. * You’ll work directly with the CPO, CTO, and founding team—not as a final execution layer. * You’ll receive competitive compensation, health insurance, meal vouchers, and significant founding equity—structured so upside matters if the company captures the opportunity we’re building. * This is a role for someone who sees frontend as a first-class product—not decoration. **What Impact Will You Have?** * **Operational Architecture & UX:** You’ll design the product’s frontend architecture (state, remote data, errors) and build dashboards, complex tables, filters, and analytical views powered by real data. * **Complex Interfaces:** You’ll implement geospatial interfaces, timelines, document views, and build document uploads and management with progress tracking, error handling, and resumable operations. * **AI Integration:** You’ll integrate copilots into workflows—including streaming outputs, intermediate states, model errors, and human approval checkpoints. * **Auditability & Trust:** You’ll create components for permissions, audit trails, sources, citations, evidence, and sensitive actions. * **Performance & Quality:** You’ll optimize client-side performance (bundle size, lazy loading, virtualization) and work with specs, coding agents, and tests to raise standards for accessibility and visual quality. **Who Are We Looking For?** * **Track Record:** Experience building complex product interfaces (not marketing sites), with strong production expertise in React, Next.js, and TypeScript. * **State Management:** Deep experience with loading states, error states, retries, streaming, and polling. * **Product Vision:** Judgment on visual hierarchy, information density, and operational UX in dashboards and data-heavy interfaces—supported by reasonable testing and real-world client-side performance optimization. * **AI-Driven Mindset:** Experience—or genuine enthusiasm—for working with coding agents (e.g., Codex, Claude Code, Gemini, or equivalents), using specs and rigorous review. * **Bonus Points:** Experience with chat/copilot interfaces, token streaming, AI-assisted workflows, or background in operational/data-heavy products (fintech, healthtech, observability, analytics). **Tech Stack** We value equivalent experience and sound judgment for building complex production interfaces: * **Core:** Next.js (ideal), or alternatives such as Remix / React Router, TanStack Start, or Vite + React. * **Language:** TypeScript (ideal); modern JavaScript works if supported by strong maintainability and progressive typing practices. * **UI & Components:** shadcn/ui (ideal), or alternatives such as Radix UI, Tailwind UI, Chakra UI, or MUI. * **Visualization:** D3, visx, Observable Plot, Recharts, Mapbox, MapLibre, Leaflet, or equivalents. * **Developer Workflow:** coding agents, AGENTS.md, Skills/SKILLS, UI specs, and SDDs using OpenSpec/Spec Kit. **Our Commitment to You** * **Competitive Compensation:** EUR 70,000–90,000 gross annually, commensurate with demonstrated experience. * **Skin in the Game:** Significant founding equity aligned with impact, seniority, and timing of entry. * **High-Performance Setup:** MacBook Pro with your choice of configuration, 40" Dell monitor, keyboard and mouse of your choice, and Herman Miller (or equivalent) chair from day one. * **Personal Well-being:** Health insurance and meal vouchers. * **Full Autonomy:** True ownership over the web experience, collaborating closely with a senior founding team, on-site in Madrid, with rapid decision-making. Data Protection The personal data you share with us during this process (CV, contact details, professional information, communications, and interview inputs) will be processed by Naiian solely to manage your application for this position—and, if you provide explicit consent, for future selection processes compatible with your profile. The legal basis for processing is the implementation of pre-contractual measures at your request (Art. 6.1.b GDPR) and, where applicable, your consent (Art. 6.1.a GDPR). Your data will be retained only for as long as necessary to manage your application, and—if you authorize retention for future opportunities—up to a maximum of one year, unless you exercise your right to erasure. We do not carry out automated decision-making producing legal or similarly significant effects. You may exercise your rights of access, rectification, erasure, objection, restriction, and data portability, as well as withdraw consent, at any time by writing to the contact address provided in the application form. You also have the right to lodge a complaint with the Spanish Data Protection Agency (www.aepd.es). — Naiian Recruiting Team