Senior Software Engineer

About usZayyh is an Australia-based health technology startup building a mobile app and a connected wearable band, launching on iOS and Android at the same time. Our engineering team works on-site in Islamabad. We are a small team, so every engineer shapes the product, the architecture and how we build.The roleWe are hiring a senior engineer to design and build across the whole system: the mobile app, the native code beside it and the backend behind it. This role is not limited to one layer. You will take a problem from an open question to a researched design, then to working software on a real phone, and you will be trusted to choose the approach.The work spans React Native and TypeScript, Swift and Kotlin, Bluetooth LE, health data, Postgres, serverless backend functions, and AI features. Nobody knows all of it on day one. We are looking for someone who learns the unfamiliar parts quickly and carefully and who thinks a problem through before writing code.What you'll doDesign systems end-to-end: how data moves from a wearable to the phone to the cloud, and how it stays correct, private, and in sync when connections drop.Build features across the stack: React Native screens, native modules in Swift and Kotlin, database schemas and migrations, and backend functions and APIs.Turn Figma designs into production UI with every state handled: loading, empty, error, offline, long text, large text sizes, and reduced motion.Research before you build: read platform docs and vendor SDKs, compare options, run small experiments, and write a short design note with a recommendation.Solve the hard problems: data that is wrong, slow or missing, and bugs that only appear on a real device.Review your teammates' code, and raise the bar on quality and testing.Shape the architecture as the product grows, and mentor other engineers.What you bring6+ years of professional software engineering, including at least 3 years on mobile apps that shipped to the App Store or Google Play.Strong TypeScript and production React Native experience. Deep native mobile experience counts too, if you are keen to work in React Native.Production code in Swift or Kotlin beyond UI screens: a native module, background work, Bluetooth or other platform APIs.Backend and database design: you have designed relational schemas, written migrations, built APIs, and thought hard about security, access control and data integrity. Postgres preferred.System design you can defend: you have made architecture decisions in production and can explain what you chose, what you rejected and how it turned out.Research and critical thinking: you dig into unclear problems, test your assumptions against evidence, question requirements (ours included) when the evidence points elsewhere, and say plainly when something is still unknown.Clear written and spoken English: design notes, pull request descriptions, and explaining trade-offs to people who are not engineers.Nice to haveBoth Swift and Kotlin in production.Bluetooth LE (CoreBluetooth, Android BLE), background execution on iOS and Android, or wearable integrations.HealthKit, Health Connect, or other health and fitness data.Offline-first apps and data sync.Supabase, Postgres row-level security, or serverless functions.Features built on LLM APIs.Animation and gesture work in React Native (Reanimated, Gesture Handler).Experience at an early-stage startup.How we workEvery change goes through a pull request, code review, and automated checks.A feature is done when it works on a real iPhone and a real Android phone, not when the tests pass.Before big changes, we write short design notes, and we record why each decision was made.Small team, direct communication, and real ownership. You will work closely with the founder and the rest of the engineering team.What we offerA competitive salary in PKR, discussed at the interview. A MacBook, plus test iPhone and Android devices and our wearable. Real ownership of architecture decisions in a product launching on two platforms. On-site at our office in Bahria Town Phase 7, Islamabad, Monday to Friday, 10 am to 6 pm. A full-time role.How to applyApply with your CV and your answers to the four questions below in a single PDF.1. A link to one app on the App Store or Google Play, and which parts of it you built yourself. 2. The hardest technical problem you have solved: what was wrong, how you found the cause and what you changed. 3. A system you designed or helped design: its main parts, one trade-off you made and what you would do differently now. 4. Your current and expected monthly salary in PKR, and your notice period.We shortlist candidates based on these answers, so a CV on its own will not reach the next step. This role is on-site in Islamabad and open to Islamabad-based candidates only.