Senior Software Engineer

Zayyh is an Australia-based health technology startup developing a mobile app and a connected wearable band, launching simultaneously on iOS and Android. Our engineering team operates on-site in Islamabad, where every engineer plays a crucial role in shaping the product, its architecture, and the development process. We are seeking a senior engineer to contribute across the entire system—from mobile app interfaces and native code to backend services. This role involves taking open-ended problems through research, design, and implementation, with the autonomy to choose the best technical approach.

Key Responsibilities
- Design end-to-end systems managing data flow from wearable devices to phones and cloud, ensuring data accuracy, privacy, and synchronization despite connectivity issues.
- Develop features across the full stack, including React Native screens, native modules in Swift and Kotlin, database schemas and migrations, as well as backend functions and APIs.
- Translate Figma designs into production-ready UI, handling all states such as loading, empty, error, offline, and accessibility considerations like large text and reduced motion.
- Conduct thorough research before implementation by reviewing platform documentation, vendor SDKs, running experiments, and producing concise design notes with recommendations.
- Address complex challenges such as incorrect, slow, or missing data and bugs that only appear on physical devices.
- Participate in code reviews to maintain high standards of quality and testing.
- Influence and evolve the product architecture as it grows, while mentoring junior engineers.

Required Qualifications
- Minimum of 6 years professional software engineering experience, including at least 3 years working on mobile apps released on the App Store or Google Play.
- Strong expertise in TypeScript and production-level React Native development; deep native mobile experience is valuable, especially if interested in React Native.
- Proven experience writing production Swift or Kotlin code beyond UI screens, such as native modules, background tasks, or Bluetooth and platform API integrations.
- Solid backend and database design skills, including relational schema design, migrations, API development, and a strong focus on security, access control, and data integrity, preferably with Postgres.
- Demonstrated ability to make and defend system design decisions in production environments, explaining choices and trade-offs clearly.
- Strong research and critical thinking skills, with the ability to question assumptions, validate requirements, and communicate uncertainties transparently.
- Excellent written and verbal English communication skills for documentation, design notes, and explaining technical trade-offs to non-engineers.

Preferred Qualifications and Benefits
- Experience with both Swift and Kotlin in production environments.
- Knowledge of Bluetooth LE (CoreBluetooth, Android BLE), background execution on mobile platforms, or wearable device integrations.
- Familiarity with health and fitness data platforms such as HealthKit or Health Connect.
- Experience building offline-first applications and handling data synchronization.
- Exposure to Supabase, Postgres row-level security, or serverless backend functions.
- Development of features using large language model (LLM) APIs.
- Skills in React Native animation and gesture handling libraries like Reanimated and Gesture Handler.
- Previous experience working in early-stage startups.

Additional Information
Our development process includes mandatory pull requests, code reviews, and automated checks. Features are considered complete only when fully functional on real iPhone and Android devices. Before major changes, short design notes are written to document decisions. The team is small, promoting direct communication and genuine ownership, with close collaboration alongside the founder and engineering colleagues.

We offer a competitive salary in PKR, a MacBook, test devices including iPhone, Android phones, and our wearable band. This is a full-time, on-site role based in Bahria Town Phase 7, Islamabad, working Monday to Friday from 10 am to 6 pm. Candidates must be Islamabad-based.

Applicants are requested to submit a single PDF including their CV and answers to the following:
1. A link to one app on the App Store or Google Play, specifying which parts were built by you.
2. Description of the hardest technical problem you solved, including diagnosis and resolution.
3. Overview of a system you designed or contributed to, highlighting key components, a trade-off made, and what you would do differently now.
4. Your current and expected monthly salary in PKR, along with your notice period.

Applications lacking these details will not be shortlisted.