Medior Frontend Engineer

Amsterdam, on-site preferred (remote possible +/- 1 hour CET)

full-time

Role overview

We're hiring a Medior Frontend Engineer to help us build the interfaces that make Bonnie real, the Dashboard our customers live in every day, the surfaces their guests touch (web chat, WhatsApp, and what comes next), and bonnie.ai itself, which we consider a first-class part of the product.

You'll join a small, AI-native engineering team that has moved past "uses AI tools" into a full agentic coding workflow. The team is backend-heavy today and still maturing how it works — you'd be our first real frontender, with the room (and the mandate) to shape that. Claude Code, Codex, Cursor, and friends are in the loop on every change. You'll own real surfaces from idea to production, partner closely with our experienced UI/UX designer, and ship the moments where Bonnie meets a real guest at a restaurant at 9:47pm on a Friday.

What you will do

• Ship the Dashboard that hundreds of restaurants already use daily | Where restaurant owners configure Bonnie, review conversations, and trust Bonnie with their phones. You'll make it faster, clearer, and more delightful.
• Build the end-user channels | A customisable WhatsApp widget that lets a guest start a conversation with Bonnie from a restaurant's website, the web chat experience, embeddable components, future surfaces. Voice is mostly backend, but the web and chat surfaces are yours.
• Help us evolve how Bonnie is configured | We're moving from one large prompt into a composable, schema-driven configuration model with live preview, validation, and building blocks restaurant staff can pick up without thinking about prompts at all. The frontend is the heart of this and a major in-flight initiative you'll have real influence over. And as Bonnie expands beyond restaurants and beyond calls, this is where you'll help define what the next surfaces look like..
• Own bonnie.ai as a product surface | Not just a marketing site, the first conversation we have with every customer.
• Make Bonnie feel like a person, not a feature | Live transcripts, call playback, configuration, simulations, turning audio and conversation into legible, editable, trustable UI is the core craft.
• Wire in RevenueOperations (RevOps) and growth where it helps, working closely with our sales team | Customer.io flows, in-product engagement, lifecycle touches, analytics instrumentation. If you're curious about the loop between product and growth, you'll have room to play.
• Set the bar | You'll shape our component system, accessibility standards, performance budgets, and how we use AI across the whole dev loop.

What your first 90 days might look like

• Weeks 1-4 | Ship to the Dashboard and the assistant configuration flow. Get fluent in the codebase, our conventions, and how we work with Claude Code, Codex, and Cursor day to day. Replace one rough edge with something you're proud of.
• Weeks 5-8 | Take the lead on one of our two biggest surfaces, either the new configuration experience (schema-driven forms, live preview, composable building blocks) or the WhatsApp widget (the embeddable web entry-point for guest conversations). Own it end to end with our designer.
• Weeks 9-12 | Help us scope and start the next push. You're now setting the technical direction of the surfaces you own.

Who we are looking for

• 3+ years building production frontends in React and TypeScript. You're past the framework debate stage and have opinions about state management, forms, and where complexity belongs.
• You've shipped real products with Tailwind, a headless component library (Radix, React Aria, shadcn, or similar), and a serious data layer (TanStack Query or equivalent).
• Comfortable working with APIs. You're at home with REST/JSON, reason about contracts before writing the call, and know when to push back on the backend.
• You're strong on forms and configuration UIs (react-hook-form, Zod, or similar) and have opinions about how to keep them sane as they grow.
• You deliver clean, accessible, well-tested code, and you know when to skip the test and ship the prototype.
• You care about UX, not just code. You'll push back on a design when something feels off, and you'll show up with alternatives. You'll thrive working closely with an experienced designer who'll push back on you too.
• You're AI-native. You ship with Claude Code, Codex, or Cursor in the loop, you've thought about how agentic workflows change the way frontends get built, and you have a take.
• You're hands-on and don't wait to be told what's next. Comfortable owning a surface end to end, from product conversation to design partnership to deploy.
• Ideally based in or willing to relocate to Amsterdam, remote is possible for the right person.

Bonus points if you have:

• Built schema-driven UIs, JSON Schema forms, dynamic form rendering, config-to-UI tooling, builder or editor experiences.
• Built real-time, audio, or telephony UIs (Twilio Voice SDK, LiveKit, WebRTC, anything that streams).
• Built embeddable widgets that live on someone else's site without breaking it.
• Built authentication and authorization flows (OAuth, OIDC).
• Shipped marketing sites that perform (Next.js, Astro, or otherwise).
• Touched RevOps tooling (Customer.io, Segment, PostHog) or built in-product growth surfaces.
• Done 0 to 1 work at an early-stage startup, or shipped something of your own.

How we work

• Small team, big ownership | You'll touch the things that matter, not the tickets nobody wants.
• AI in the loop, everywhere | Claude Code, Codex, and Cursor are part of the team. We're moving toward a fully agentic coding workflow, and we mean it. The bar isn't "uses AI tools", it's "ships better work because of them."
• Close design partnership | You'll work daily with an experienced UI/UX designer who treats the work as a real collaboration.
• On-site preferred, remote possible | Most weeks you're in our Amsterdam office, the rest is up to you. Every ~3 months we bring the whole team together in person.
• Ship daily, talk weekly | Short loops, fewer meetings, real demos.
• Honest by default | Yes, we're Dutch.

Why you'll love working at Bonnie

• Meaningful equity | through our Employee Stock Option Plan (ESOP). You'll feel the upside.
• Competitive salary | we'll be transparent about the band when we talk.
• Full setup | a fresh MacBook, the tools you want, and a budget for the rest.
• An office worth coming to | daily fresh-cooked lunch, great coffee, a pool table, and the best team vibe in Amsterdam.
• Quarterly team events | we celebrate the wins together.
• A real product with real customers | Loetje, 3WO, Dudok, Ron Gastrobar, and a growing list across 14 countries already trust Bonnie with their phones.

About Bonnie

Local businesses are the backbone of our communities, yet most tech is built for enterprises. Our founders spent 12+ years building software for this space and scaled a platform that helped 55,000+ local businesses grow. We saw the gap, missed calls, lost revenue, and teams stretched thin.

Bonnie is our answer. The conversational AI assistant that ensures every call is answered and every opportunity is captured, across phone, WhatsApp, and chat. We're giving local businesses the tech they deserve.

Ready to build?

If the idea of owning the interfaces between Bonnie and the people who actually use her gets you excited, we'd love to talk. Apply here with your CV, a link or two to things you've built, and (if you feel like it) a sentence on the most interesting thing you shipped this year.