Product Engineer (Frontend Leaning)

MarvelX AI; Amsterdam; On-site; EUR 55,000 - 95,000; Full time

Job summary

MarvelX AI is building frontend experiences for AI systems in heavily regulated industries. You’ll own the look, feel, and performance of core products, translating AI-driven workflows and live data streams into intuitive interfaces.

You’ll define frontend architecture, establish our design system, and collaborate with cross-functional teams to ship production-grade interfaces in a fast-paced startup environment.

Qualifications

• Proven experience building production web apps with modern stacks.
• Strong command of React and TypeScript.
• Solid experience with responsive design and TailwindCSS.
• Experience integrating REST and GraphQL APIs; debugging data flows.
• Familiarity with real-time streaming tech (WebSockets, SSE, GraphQL subscriptions).

Responsibilities

• Build, optimize, and maintain modern web apps using React and TypeScript.
• Design clean, responsive UIs with TailwindCSS and custom CSS.
• Integrate backend and AI APIs to deliver data-rich interfaces.
• Work with real-time streaming data to visualize dynamic interfaces.
• Collaborate with product, design, and AI teams to ship fast, reliable products.
• Implement performance, accessibility, and maintainability best practices.

Skills

React

TypeScript

TailwindCSS

REST APIs

GraphQL

WebSockets

Real-time data

UI design

Tools

Plotly

D3

Job description

MarvelX is building highly specialized AI agents for the most complex, heavily regulated industries. Think insurance claims, compliance, support. Automated by AI that actually works in the real world. The opportunity is massive, and we’re moving fast.

We’re looking for a Frontend Engineer who can turn complex data and real-time interactions into seamless, beautiful interfaces. Someone who thrives at the intersection of performance, design, and API-driven data. You’ll work directly with our founders and tech leads to build the user-facing layers of our AI systems — the parts that clients touch, trust, and depend on.

This isn’t a typical frontend role. It’s an early seat on the rocket ship.

Mission

As a Frontend Engineer, you’ll own the look, feel, and performance of MarvelX’s core products. You’ll translate AI-driven workflows and live data streams into intuitive, production-grade user experiences. You’ll help define our frontend architecture, establish our design system, and shape how users interact with AI in high-stakes environments.

What you’ll be doing

• Build, optimize, and maintain modern web applications using React and TypeScript.
• Design clean, responsive UIs with TailwindCSS and custom CSS for pixel-perfect control.
• Integrate deeply with backend and AI APIs to create seamless, data-rich user experiences.
• Work with real-time streaming data to visualize and update interfaces dynamically.
• Collaborate closely with product, design, and AI teams to translate ideas into fast, reliable products.
• Implement best practices for performance, accessibility, and maintainability across the stack.
• Contribute to component libraries and internal tooling to accelerate development velocity.

What you’ll need

• 2–4 years of experience building production-grade web applications.
• Deep expertise in React and TypeScript.
• Strong command of TailwindCSS, custom CSS, and responsive design principles.
• Experience integrating REST and GraphQL APIs — and debugging complex data flows.
• Familiarity with real-time/streaming technologies (e.g. WebSockets, SSE, or GraphQL subscriptions).
• Strong eye for design and user experience — you care about the details.
• Comfortable shipping fast, iterating often, and owning the product experience end-to-end.

Bonus

• Experience with data visualization (e.g. Plotly, D3, or Recharts).
• Understanding of AI-driven applications or dashboard design.
• Previous experience in a fast-paced startup or product-led environment.