Senior Product Engineer (React / React Native)
About 4goo
We're building a social network for web and mobile — think rich user profiles, real-time messaging,
media feeds, and the scale that comes with it. Our backend is Go microservices on Kubernetes, and
every contract between backend and clients is formalised: OpenAPI for HTTP, AsyncAPI for the
realtime layer.
We're building our entire client layer from scratch — web, iOS and Android — as one monorepo owned
by one team. The first commit hasn't been written yet. We haven't launched publicly, the design
system is finished in Figma and being exported to code, and whoever joins now shapes how this gets
built rather than inheriting someone else's decisions.
The Role
You own product surfaces end to end — one person, one feature, three platforms. Not "the web
version" or "the iOS version." The feature.
Next.js on web, Expo on iOS and Android, one monorepo, with most UI written once through a universal
component layer. That means what you build has to be genuinely good in a browser and genuinely good
on a phone — which are not the same problem, even from the same code.
You're one of the first two hires on this team, so the patterns are partly yours. You're not working
a ticket queue — you're deciding what needs building, saying what needs changing, and making it
happen.
What You'll Work On
- Feed, reels and stories. Virtualized lists that stay smooth under real data, and a vertical
video pager with preloading and a memory budget that actually holds. This is where most
cross-platform apps fall over. If you've solved it before, we want to talk.
- Real-time chat and in-app notifications. WebSockets against an AsyncAPI-defined contract:
message ordering, optimistic updates, reconnection, and a chat window that stays correct while
five things happen at once.
- Media. Capture, chunked and resumable upload, playback, in-app editing — across three
platforms with genuinely different capabilities.
- Building on the generated design system. The Figma is finished and exported to code. You'll
compose product surfaces from those primitives in Storybook — and push back when a primitive is
wrong rather than working around it.
- Performance as an owned metric, on native and web both — measured, budgeted, and defended in
review.
What We're Looking For
Must have:
- 5+ years building with React, with strong TypeScript
- React Native shipped to production, ideally to both app stores
- Comfortable on web and native both — you're not looking to specialise in one and tolerate the other
- You've built something at this complexity before — real-time, media, infinite feeds, optimistic
updates. You know why the second one is harder than the first
- Performance is something you measure, not something you assert: frame rates, memory, bundle size,
re-render cost
- You own things. You pick up the problem, decide what needs doing, and say what you're doing.
Nobody here will be assigning you tickets
- You think about the product. You'll notice when something in the design won't work before you
build it, and say so — we'd rather have that conversation than ship the wrong thing on time
Strong plus:
- Storybook as part of how you actually work, not an afterthought
- Building against a design system rather than one-off screens
- Universal / cross-platform UI layers — Tamagui, react-strict-dom, Unistyles or similar
- Next.js in production
- Expo and EAS, including OTA updates
- Video-heavy or feed-heavy consumer products
- Media capture, upload and playback pipelines
- Real-time — reconnection, ordering, presence
- Generated clients from OpenAPI or AsyncAPI specs
- Working in a monorepo
Working With AI Agents
We build with AI agents deliberately, and we're looking for people who are genuinely good at it —
not "I've tried Copilot."
The reason is specific. The design system is finished. The backend contracts are fixed and
machine-readable. The team is small on purpose. Our constraint isn't deciding what to build — it's
implementation throughput at a quality bar, which is exactly where agents earn their keep and
exactly where sloppy use costs you.
We mean the practical skill: giving an agent the right context, scoping work so the output can
actually be verified, knowing when to hand off and when to write it yourself, and reviewing
generated code properly.
If you have opinions about how this should work, we want to hear them.
What Good Looks Like in This Role
In your first month you're shipping real screens to web and native from the shared design system —
and already arguing about the patterns rather than just following them.
Six months in, you own a surface. Feed, chat, media — whichever fits you. It works on every
platform, the people around you route questions about it to you, and its performance story is
something you can defend with numbers.
Stack
Decided: React · Next.js · React Native · Expo (EAS) · TypeScript · monorepo · Storybook ·
OpenAPI + AsyncAPI generated clients · WebSockets · GitLab CI
Still open: the universal UI approach · data and caching layer · testing strategy. You'll have a
say.
Backend is Go microservices on AWS — you won't write it, but you'll design against it.
Interview Process
1. Intro call — what you've built, what you want to own.
2. Technical conversation about the real problems in front of this team. No whiteboard algorithms.
3. Offer.
What We Offer
- A codebase you start rather than inherit
- Real influence on architecture, before launch, while the decisions are still open
- Ownership of whole features across three platforms, not slices of one
- A small team by design, not by circumstance
- Direct access to decision-makers — no layers between you and the people setting direction
- Remote-friendly, async-first culture
- Competitive compensation based on experience
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*Please include something you've built — ideally something with a real feed, real video, or real
users — and, if you can, a sentence on how you actually use AI agents day to day.*