Frontend Engineer; React​/TypeScript

We’re hiring builders who want to solve meaningful problems with AI.
Our team values clarity, speed, and doing work that lasts.

MarvelX builds specialized AI agents for complex and highly regulated domains such as insurance claims, compliance, and enterprise support. Our systems run in real world environments where accuracy, reliability, and clarity matter. The market is enormous and we are growing quickly.

We hire Product Engineers, not narrow specialists. You own features end to end: the services and data behind them, the interface in front of them, and the product decisions in between. You will work directly with the founders and engineering leads to shape the systems and surfaces our customers rely on every day. We do not split work across a backend team and a frontend team that throw it over a wall.

Everyone here ships across the stack and reasons about the whole product.

This is not a maintenance role. It is a chance to shape a product at an early and meaningful stage. We work on-site in Amsterdam three or more days a week.

Every Product Engineer at MarvelX is fullstack with a lean. This role leans frontend.

You will own the user-facing surfaces that make our AI agents usable, reliable, and clear. You will turn complex AI behavior into interfaces that feel calm and trustworthy for users in regulated industries. You will still build and reason about the backend slice that feeds your interface and define the API contracts with the team, but the center of gravity is the frontend.

Design and build user-facing features in React and Type Script

Create responsive, accessible UIs that hold up against real production data

Build real-time interfaces for streaming AI output (Web Socket, SSE)

Build the backend slice that feeds your interface, in Python and FastAPI, with the team

Integrate with backend APIs, handling loading, error, and optimistic update states cleanly

Diagnose and fix performance issues, perceived and measured (LCP, TTI, bundle size)

Contribute to or help establish the component library and design system

Two to five years building production React applications with Type Script

Deep understanding of React patterns, hooks, rendering lifecycle, and state management

Strong CSS skills (Tailwind, CSS-in-JS, or strong vanilla CSS) and responsive design instincts

Comfort owning a feature end to end, including the backend slice that supports it

Willingness and ability to work across the stack, backend included, when the feature needs it

Product sense: you reason about the user and the outcome, not only the code

Strong testing instincts (unit, integration, E2E)

Experience building UIs for B2B / enterprise customers (data tables, role-based views, multi-tenant dashboards)

Component library or design system contribution

BYOC / on-prem product experience (offline-capable UIs, environment-specific config)

Previous startup experience and comfort in fast moving environments

If you are excited by owning real interfaces end to end and putting AI into the hands of users in regulated industries, we would love to meet you.

Based in Amsterdam, at least 3 days a week in the office. Work eligibility in the Netherlands required; we are not able to sponsor visas in the Netherlands yet.

The audit-ready AI workforce for modern insurance carriers and TPAs.