# JC Yap (yjctech.dev) — Architecture & Engineering Profile

> Personal engineering vault and production architecture documentation of JC Yap: Cross-Border Mobility Infrastructure & Deterministic AI Systems Architect.

## Core Philosophy & System Invariants

- Fail-Closed by Design: Any anomalous pricing quote, state transition, or ledger mutation trips an immediate circuit breaker. Default to rejection over corrupt execution.
- Evidence Over Inference: Autonomous agent decisions and ETL events must provide proof chains (SHA-256 cascade Merkle roots) before state commitment.
- Grounded in Physical Reality: Systems are bound to physical constraints (geofence, border checkpoint crossing delays, currency exchange limits, driver shift boundaries).

## Key Production Systems

### 1. Autonomous Dynamic Pricing Engine
- Architecture: 3-tier hierarchical evaluation (Base route calculation -> Supply/Demand surge matrix -> Dispatch leveling buffer).
- Invariant: `MarginDelta >= -5.0% && CeilToNearest(10)`.
- Stack: Rust, Tokio Async, PostgreSQL.
- SLA: < 12ms p99 latency, 99.99% availability.

### 2. DataNexus Invariant Pipeline
- Architecture: Zero-tolerance stream ingestion and nanosecond quarantine isolation.
- Stack: TypeScript, Python, Redis, Immutable Append Ledger.
- Metric: 0.00% dirty data leakage into cross-border reconciliation journals.

### 3. Route3 Stealth Browser Runtime
- Architecture: Decoupled from traditional Chrome DevTools Protocol (CDP) to prevent anti-bot detection; uses UInt32LE length-prefixed streaming protocol.
- Supported Hosts: 6 distinct runtime environments.
- Stack: Chrome Extension Manifest V3, TypeScript, WebAssembly.

### 4. Synapse: Nightly Dream Cycle Engine
- Architecture: WhatsApp-based bi-directional conversation collector + offline nightly cognitive distillation pipeline.
- Logic: Dual-stage deduplication (Levenshtein token distance + embedding cosine similarity) synthesizing into 1,000+ Obsidian knowledge vault notes.
- Stack: Python, WhatsApp Cloud API, Vector Embeddings, Obsidian Markdown.

### 5. Deterministic Dispatch Control Tower
- Architecture: 51-state deterministic Finite State Machine (FSM) governing complete cross-border ride lifecycle.
- Security: 4-tier role permission matrix (Passenger, Driver, Dispatcher, Risk Engine) + GPS hardware fence verification gates.
- Stack: Go, Node.js, WebSockets, PostGIS.

## Architectural Specifications & RFCs

- RFC-042: Fail-Closed 3-Tier Dynamic Pricing Specification
- SPEC-089: Route3 Zero-CDP Browser Interception Protocol
- RFC-116: 51-State Deterministic Mobility Dispatch FSM
- METHOD-014: Zero-Touch Multi-Agent Orchestration & Dream Cycle

## Contact & Links

- Website: https://yjctech.dev
- Email: contact@yjctech.dev
- GitHub: https://github.com/jc-yap89
- Bio CLI: `curl -sL https://yjctech.dev/bio`