Sr. Front End Engineer

Knotch is redefining the future of websites in the age of AI.
The way people discover, engage with, and consume content is fundamentally changing. Customers now find information and make decisions through AI, increasingly with an agent acting on their behalf. Most brand digital presences were never built for this journey. Knotch is the AI-native infrastructure that closes that gap, giving brands the ability to meet every customer, and every agent, with the right experience at the right moment, and to adapt as fast as AI and consumer behavior keep changing.
Our platform combines content intelligence, measurement, and agentic AI to show enterprises what content works, continuously optimize their sites, and deliver measurable business outcomes. At the center is ACE (Agentic Content Engine), which moves brands beyond static websites toward intelligent, adaptive ones that keep improving.
We work with some of the world’s most recognizable companies. Our culture is fast-paced, entrepreneurial, and highly adaptable. We move quickly, test ideas, and evolve with our customers. We’re looking for exceptional people who want to help shape how leading brands show up in an AI world.

About the role
You’ll split your time between two front ends at very different stages.

Knotch ACE, generates web experiences from AI in real time. Rather than serving fixed pages, our backend streams typed component descriptions and the front end assembles them into a React tree as they arrive. It's Next.js App Router and Type Script in a monorepo, live for several enterprise brands, each with its own theming and deployment.

Knotch One is a mature React application that customers use daily, built on Redux, GraphQL and styled-components, with data visualization at its core.

Between them there's a good mix of greenfield design work and the kind of careful change you make in a codebase with real users. We're looking for someone who's happy doing both.

Responsibilities

Build features across both applications, working to each one's existing conventions

Develop the component system that renders streamed, AI-generated layouts — schemas, renderers, and the contracts between them

Work on multi-tenant theming: design tokens, per-brand configuration, client-specific variants

Build and maintain embeds that run our product inside customer websites

Set standards for testing, accessibility, and performance

Work with backend engineers on API and streaming contracts, including where the line between front end and backend actually sits

Write the approach down before you build it, and raise blockers, risks and disagreements early rather than after they've cost time

Ramp yourself up on unfamiliar parts of the product and codebase, and mentor others through code review, pairing, and written design

Qualifications

6+ years building React applications in production

Type Script day to day, including typing data that arrives at runtime

Next.js App Router, or another framework with a server/client rendering split — Remix, Nuxt, Svelte Kit

Experience in a large codebase with history, where the work meant fitting into earlier decisions rather than starting clean

CSS at scale — utility-first (Tailwind) or CSS-in-JS (styled-components, Emotion), and styling systems built on tokens or theme objects.

Accessible UI work — keyboard navigation, ARIA, and testing against WCAG

Data visualization — ECharts, D3, Recharts or similar

Writing tests alongside features — Vitest, Jest, Testing Library or similar

Clear written communication, and a track record of working without close supervision: scoping your own work, unblocking yourself, and telling people what you need

Nice to Have

Runtime schema validation — Zod, Valibot or similar

Streaming or incremental UI — SSE, Web Sockets

Monorepo…