Full Stack Engineer

About ONLYQONLYQ is building the world’s most advanced ultra-slim, clinical-grade health wearable—combining premium materials (ceramic, sapphire, FKM), multi-sensor physiology (PPG, ECG, EDA, Temp, IMU), and real-time AI analytics.Backed by Cymetree Projects LLP, a high-growth multi-vertical enterprise (USD 340M projected revenue this year), ONLYQ is a self-funded, long-term premium hardware–AI ecosystem with global ambitions.We’re assembling a world-class team to launch our Gen-1 wristband and mobile app—designed to compete with WHOOP, Oura, Garmin, and Apple.Role OverviewWe are looking for an exceptional Senior Full-Stack Mobile Developer with deep experience in Bluetooth Low Energy (BLE), real-time sensor streaming, and native mobile development (iOS + Android).This is a core team, high-ownership role responsible for building the ONLYQ mobile app from scratch—architecture, BLE integration, data pipelines, backend APIs, and production-quality UI.You will work closely with our firmware, sensor, and AI teams to deliver a world-class health and wellness experience.What You Will Build✔ Native iOS and Android apps for ONLYQ (Swift + Kotlin)✔ High-stability BLE pipeline for PPG/ECG/EDA/Temp/IMU streaming✔ Real-time data ingestion, processing, caching & cloud sync✔ Backend API layer (Node.js or Python)✔ AI/ML model integration (sleep, HRV, stress, readiness)✔ Beautiful dashboards and wellness visualizations✔ Secure user authentication, subscription, and cloud services✔ CI/CD pipelines & scalable architecture for future V2/V3 hardwareKey ResponsibilitiesMobile DevelopmentBuild native iOS apps using Swift, SwiftUI, CombineBuild native Android apps using Kotlin, Jetpack ComposeImplement CoreBluetooth & Android BLE stackOptimize MTU, GATT, reconnection logic, and background syncEnsure ultra-reliable sensor data capture (5–50 Hz)Backend & APIBuild REST + WebSocket APIs (Node.js or Python)Implement data storage (PostgreSQL/MongoDB)Setup cloud infrastructure (AWS/GCP)Ensure secure data flow & low-latency analyticsData & AI IntegrationIntegrate physiological AI models (Python/TensorFlow Lite)Work with our biosensor engineering teamImplement signal cleaning, annotation & time-series syncArchitecture & QualityImplement MVVM / clean architectureAutomated testing, CI/CD pipelinesOptimize for battery life, background execution & stabilityDeliver smooth, polished UI interactions with animation supportRequired SkillsMobile (Mandatory)Expert in Swift / SwiftUI / CombineExpert in Kotlin / Jetpack ComposeStrong experience with BLE GATT communicationExperience with real-time sensor data processingExperience with background services & multi-threadingBackendProficient in Node.js or Python (FastAPI)Database experience: PostgreSQL or MongoDBExperience with AWS/GCP/FirebaseWearable / Health DataUnderstanding of HR, HRV, ECG, IMU, Temp, or other biosignalsExperience working with wellness, fitness, or IoT devicesBonus SkillsExperience with TensorFlow Lite / CoreMLExperience with time-series data & signal processingExperience building subscription-based appsKnowledge of Apple HealthKit / Google FitWho Should ApplyYou are a top-tier developer with a strong engineering mindsetYou’ve worked on smartwatch / IoT / fitness appsYou want to build a global premium product from Day 1You enjoy solving deep Bluetooth, data, and architecture problemsYou want ownership—not just a coding jobWhat We Offer·                Work on one of India’s most ambitious consumer health-tech products·                High autonomy, fast decision cycles, and a world-class vision·                Competitive compensation + performance-based incentives·                Opportunity to grow into Engineering Lead / CTO as we scale·                Direct access to founders and full creative freedom