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
• --
• 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.*