Kotlin Back-End Developer

Job Description Our Client is a fast-growing HealthTech company building the Arab world's first unified health-data platform — one Arabic-first dashboard that brings together users' sleep, nutrition, activity and heart data from 15+ smart devices, powered by an AI health assistant. We're looking for a hands-on Back-End Developer to work part-time and fully remote on the core services that ingest, process and serve millions of health-data points. You'll own backend features end-to-end in a modern Kotlin + Spring Boot stack , working closely with the mobile team on clean, well-documented APIs. Key Responsibilities: Design, build and maintain backend services in Kotlin 2.x and Spring Boot 3.x Model and optimize data across PostgreSQL 17 (transactional) and ClickHouse (analytics/OLAP) Build and document clean, versioned REST APIs consumed by the iOS and Android apps Integrate and normalize data from third-party wearable/device APIs Design efficient data flows between the transactional store and the analytics layer Ensure security, encryption and privacy standards for sensitive health data Write tests, participate in code reviews, and keep technical documentation current Requirements Proven experience shipping production backend systems in Kotlin Strong hands-on Spring Boot 3.x experience Solid PostgreSQL skills (schema design, indexing, query optimization) Working experience with ClickHouse or a comparable OLAP/columnar store Comfortable designing REST APIs and working with JSON at scale Self-directed and reliable in a remote, part-time setup Good written English; Arabic is a plus Skills: Kotlin · Spring Boot · REST API design · PostgreSQL · ClickHouse Coroutines/concurrency · Gradle · Docker · CI/CD · Git Data modeling · performance tuning · secure data handling Benefits 100% remote, flexible part-time hours Modern greenfield stack with real ownership High-impact product in a fast-scaling regional HealthTech