Engineering & Infrastructure

Technology Stack & Architecture

An offline-first Android engine built with strict Clean Architecture, deterministic Room database persistence, and isolated REST AI integrations.

Clean Architecture + UDF

PhysioPilot enforces a strict inward dependency direction. The core Domain Layer is 100% pure Kotlin with zero Android framework imports, ensuring that business rules, SM-2 retention math, and clinical reasoning logic remain completely testable and deterministic.

Presentation Layer Jetpack Compose + Material 3

Domain Layer Pure Kotlin (Zero Android SDK)

Data Layer Room SQLite + Dagger Hilt

APK Intellectual Property & Security Architecture Hardened Build

R8 Bytecode Obfuscation & Class Shrinking

All production Android binaries undergo aggressive symbol stripping, control-flow flattening, and class obfuscation to protect proprietary clinical algorithms and domain models against reverse-engineering.

Cryptographically Sealed Knowledge Graph

Clinical slice trajectories, scoring blueprints, and university past questions are bundled inside an encrypted offline relational store, preventing raw data scraping or asset extraction.

Hardware-Backed Key Isolation (Android KeyStore)

User API keys and local student session telemetry are sealed using AES-256 GCM authenticated encryption backed by the device's hardware Secure Element / StrongBox.

Proprietary Offline Engine

High-performance local SQLite database engine with custom indexed B-tree architecture. Delivers sub-10ms search over 8,600+ practice questions with zero network dependence.

Encrypted Local Key Storage

When students configure their optional Google AI Studio API key, it is encrypted on-device via Android's hardware KeyStore with AES-256 GCM hardware-backed key encryption.

Gemini 2.5/3.8 Flash Client

Lightweight direct HTTPS client communicating with Google's official Gemini endpoint for Socratic clinical dialogue, with automated fallback to encrypted local clinical pearls.

Infrastructure Clarity Live Reality vs. Proposed Roadmap

Currently Live Architecture

• Marketing Website: 100% Static HTML5 / CSS / Vanilla JS deployed on Cloudflare Pages global Anycast CDN (\$0/mo hosting).
• Android Mobile App: 100% Offline-First SQLite running on the student's Android device with zero cloud server dependencies.
• AI Engine: Direct on-device HTTPS requests to Google's public Gemini API endpoint.

Target Google Cloud Architecture (On Roadmap)

• Google Cloud Firestore: Opt-in student sync for SM-2 spaced repetition review histories across phone and tablet.
• Google Cloud Run: Serverless microservices executing automated clinical provenance verification pipelines and university syllabus scrapers.
• Strict Spending Caps: Hard billing quotas and alert budgets to eliminate unexpected cloud infrastructure expenses.