I’m building a mobile app using React Native, and I need an experienced Android developer to implement a native module that handles background processing and sensor-based event detection. Scope of work: 1. Build a native Android foreground service that: - Runs reliably in the background - Is not killed by the OS (handle Doze mode, battery optimization) 2. Detect the following signals: - Screen ON/OFF state - Charging state (plug/unplug) - Basic motion detection using accelerometer (low-frequency sampling) - Optional: ambient light sensor (if available) 3. Implement logic to: - Track inactivity (e.g., screen off + no interaction) - Combine signals and trigger an event when conditions are met - Ensure low battery usage (no continuous high-frequency polling) 4. Alarm functionality: - Schedule exact alarms using AlarmManager - Ensure alarms work even in Doze mode 5. React Native bridge: - Expose native functionality to React Native via a clean module interface - Send events from native → JS when detection happens Requirements: - Strong experience with Android (Kotlin preferred) - Experience with foreground services and background execution limits - Familiarity with sensors (SensorManager) - Experience handling Doze mode and battery optimization - Experience creating React Native native modules Deliverables: - Clean, well-structured Android code - Documentation on how to use the native module from React Native - Basic demo showing detection + alarm trigger working Please include: - Examples of similar work (background services, sensors, or system-level apps) - Brief explanation of how you would prevent the app from being killed We will start with a small paid test task before proceeding to full project.