# Purna Kalyan Shakya // Senior Flutter Engineer

> Software engineer with an electronics engineering background, working primarily in Flutter, Dart, and native systems integration. Engineering focus centers on runtime predictability, offline-first architectures, and resilient developer tooling built for adverse hardware environments, bridging into native Android platform channels, C/Rust via Dart FFI, and WebAssembly (WASM).

- **Location**: Kathmandu, Nepal
- **Education**: Nepal Engineering College
- **Website**: https://shakyapurna.com.np
- **GitHub**: https://github.com/landxcape
- **LinkedIn**: https://linkedin.com/in/purnashakya
- **pub.dev Publisher**: https://pub.dev/publishers/shakyapurna.com.np/packages
- **Email**: shakyakpurna@gmail.com
- **Resume**: https://shakyapurna.com.np/resume.pdf

---

## Technical Summary
- **Primary Framework & Languages**: Flutter, Dart, Rust, Kotlin, GLSL, Bash, WebAssembly (WASM).
- **Core Engineering Paradigms**: Multithreaded Dart Isolates, Offline-First SQLite Architectures, Hardware-Accelerated CustomPainter / CanvasKit Shaders, Cryptographic Leases, Direct Binary Hardware Streaming (ESC/POS, APFS, Raw Ethernet Sockets).
- **Production Scale**: 1,500+ Active Fleet Vehicles, 100+ Commercial Transit Displays, 30+ Handheld Android POS Terminals, 10 Published pub.dev Packages, 4 Systems CLI Tools.

---

## 01 // Commercial Systems & Engineering Case Studies

### 1. Real-Time Fleet Telemetry & Map Marker Interpolator // Slash Plus
- **Scale**: 1,500+ Active Vehicles across nationwide transit routes in Nepal.
- **Problem**: High-frequency Socket.IO telemetry packets saturated Flutter's main UI isolate event loop during JSON deserialization, causing severe frame drops and halting map marker animations.
- **Solution & Architecture**:
  - Offloaded payload deserialization and validation to a persistent worker isolate pool via `isolate_runner_mixin`.
  - Batched telemetry coordinates into 3-second temporal windows.
  - Built custom ticker-driven spherical coordinate math and geodesic shortest-arc bearing interpolation, maintaining continuous 60 FPS marker motion on Google Maps without UI thread contention.
- **Extracted Packages**:
  - [`animated_marker`](https://pub.dev/packages/animated_marker)
  - [`isolate_runner_mixin`](https://pub.dev/packages/isolate_runner_mixin)

### 2. Offline-First Transit Media & Signage Player // Slash Plus
- **Scale**: 100+ Transit Displays on commercial passenger buses.
- **Problem**: Harsh operating environments with abrupt engine power cuts, frequent cellular dead zones along mountain highways, and severe thermal throttling on low-cost Android hardware.
- **Solution & Architecture**:
  - Resilient offline-first SQLite state machine with durable priority task queues, cryptographic lease verification, and atomic file swaps.
  - Native Rust/C cryptographic acceleration via `dart:ffi`, slashing cryptographic lease validation latency from 15 seconds down to 150 milliseconds (99% reduction).
  - Continuous horizontal marquee text ticker operating entirely at the RenderBox level to eliminate layout passes.
- **Extracted Packages**:
  - [`scroll_texts_widget`](https://pub.dev/packages/scroll_texts_widget)
  - [`resumable_downloader`](https://pub.dev/packages/resumable_downloader)
  - [`ffr_crypto`](https://pub.dev/packages/ffr_crypto)

### 3. Handheld Android POS Fleet & Direct Thermal Printer Engine // Slash Plus
- **Scale**: 30+ Field Android POS Devices across high-volume transit terminals.
- **Problem**: Vendor Android printer SDKs suffered from unmanaged memory leaks, thread contention, and unpredictable printer freezes during peak ticketing rushes.
- **Solution & Architecture**:
  - Direct binary ESC/POS byte streaming pipeline over low-level Android hardware interfaces, completely bypassing vendor runtime layers.
  - Rendered print layouts on an offscreen Flutter Canvas at sub-10ms latency.
  - Signed local transaction ledgers with biometric authentication gating.
- **Extracted Packages**:
  - [`clean_feature_arch`](https://pub.dev/packages/clean_feature_arch)
  - [`repository_kit`](https://pub.dev/packages/repository_kit)
  - [`biometric_secure_vault`](https://pub.dev/packages/biometric_secure_vault)

### 4. Real-Time Delivery Logistics & Dispatch Engine // Dynamic Technosoft
- **Scale**: Enterprise delivery routing and courier tracking across urban corridors.
- **Architecture**:
  - Feature-First Clean Architecture scaffolding enforcing unidirectional data flow.
  - Unidirectional BLoC state streams managing live order dispatch and GPS coordinate updates.

---

## 02 // Published Open-Source Packages & Libraries

All packages are maintained under publisher `shakyapurna.com.np` on pub.dev:

1. **[`animated_marker`](https://pub.dev/packages/animated_marker)**
   - *Description*: Smooth Google Maps marker animation engine with geodesic shortest-arc bearing interpolation and spherical coordinate math for live fleet tracking.
   - *Target*: 60 FPS Direct Vector Canvas, zero UI isolate jank.

2. **[`scroll_texts_widget`](https://pub.dev/packages/scroll_texts_widget)**
   - *Description*: High-performance continuous marquee text ticker that bypasses widget tree layout passes via dedicated Flutter Ticker painters.
   - *Target*: Zero layout overhead, constant memory footprint.

3. **[`isolate_runner_mixin`](https://pub.dev/packages/isolate_runner_mixin)**
   - *Description*: Cross-platform concurrency mixin for persistent background workers with multiplexed RPC, native OS thread execution, and universal Web/WASM compilation.
   - *Target*: RootIsolateToken bridging, zero boilerplate isolate lifecycle management.

4. **[`resumable_downloader`](https://pub.dev/packages/resumable_downloader)**
   - *Description*: Multipart HTTP range downloader with durable pause/resume, persistent SQLite scheduling, and MD5/SHA256 integrity validation.
   - *Target*: Intermittent network fault tolerance, automatic chunk resumption.

5. **[`repository_kit`](https://pub.dev/packages/repository_kit)**
   - *Description*: Pure Dart toolkit for offline-first repositories orchestrating cache-vs-remote strategies with functional `Result<T>` and `Either<AppError, T>` types.
   - *Target*: Zero raw exception leakage across domain boundaries, reactive cache synchronization.

6. **[`clean_feature_arch`](https://pub.dev/packages/clean_feature_arch)**
   - *Description*: Feature-first Clean Architecture scaffolding toolkit and CLI with Dart 3 enforcement rules, layer boundaries, and boilerplate generators.
   - *Target*: Standardized enterprise Flutter codebase architecture.

7. **[`nbody_sim_core`](https://pub.dev/packages/nbody_sim_core)**
   - *Description*: Engine-agnostic N-body gravitational simulation core models with numerical integrators (Euler, Velocity Verlet, Runge-Kutta 4th Order).
   - *Target*: 64-bit IEEE floating-point precision, O(N²) and Barnes-Hut quadtree spatial partitioning.

8. **[`nbody_sim_flutter`](https://pub.dev/packages/nbody_sim_flutter)**
   - *Description*: Flutter rendering widgets, interactive gesture viewport controls, and theme primitives for real-time gravitational N-body simulations.
   - *Target*: 60 FPS interactive celestial mechanics on Flutter Canvas.

9. **[`biometric_secure_vault`](https://pub.dev/packages/biometric_secure_vault)**
   - *Description*: Hardware-backed KeyStore/Keychain secure vault gated behind biometric prompts with sealed Result types and zero plaintext memory caching.
   - *Target*: Hardware Secure Enclave integration, zero plaintext persistence.

10. **[`ffr_crypto`](https://pub.dev/packages/ffr_crypto)**
    - *Description*: Rust-backed cryptographic engine providing high-speed RSA signature verification, AEAD encryption, and SHA hashing via `dart:ffi`.
    - *Target*: 99% latency cut (150ms vs 15s in pure Dart).

---

## 03 // Systems Tools & Homebrew Formulas

Available via Homebrew Tap `landxcape/tap`:

1. **[`mso (mac-sym-offload)`](https://github.com/landxcape/mac-sym-offload)** (`brew install landxcape/tap/mso`)
   - macOS developer SSD cache offloader and atomic symlink manager for Gradle (`~/.gradle`), Android SDK (`~/.android`), and Xcode build artifacts. Reclaims 100+ GB host SSD with APFS volume cloning and rollback safety.

2. **[`camgylph`](https://github.com/landxcape/camgylph)** (`brew install landxcape/tap/camgylph`)
   - Real-time CLI camera capture utility converting live webcam video streams into colored ANSI terminal glyphs using SIMD color mapping and hardware video decoders.

3. **[`rscan`](https://github.com/landxcape/rscan)** (`brew install landxcape/tap/rscan`)
   - High-speed Layer 2 raw Ethernet ARP subnet discovery and multithreaded non-blocking TCP port scanner written in Rust.

4. **[`synkrophase`](https://github.com/landxcape/synkrophase)** (`brew install landxcape/tap/synkrophase`)
   - Zero-latency local network audio and media playback protocol synchronizer with precision monotonic clock drift compensation (< 500µs drift) and UDP multicast beacons.

---

## 04 // Interactive Package Lab Sandboxes

The web platform features interactive executable developer sandboxes running client-side on WebAssembly / WebGL:
- **N-Body Celestial Mechanics Sandbox**: Gravitational simulation canvas with RK4 integrator and interactive pointer wells (`https://shakyapurna.com.np/#/lab/nbody_sim_flutter/sandbox`).
- **Zen Grid Dynamic Wavefield Observatory**: Procedural trigonometric wavefields, interactive raycasting, and coordinate crosshair telemetry (`https://shakyapurna.com.np/#/lab/zen_grid_observatory/sandbox`).
- **Vector Marker Telemetry Sandbox**: 60 FPS vehicle motion and spherical bearing rotation on Google Maps (`https://shakyapurna.com.np/#/lab/animated_marker/sandbox`).
- **Marquee Ticker Bench**: Zero-layout-overhead text streaming (`https://shakyapurna.com.np/#/lab/scroll_texts_widget/sandbox`).
- **Repository Kit Offline Sync**: Fault-injection network emulator with functional error handling and optimistic writes (`https://shakyapurna.com.np/#/lab/repository_kit/sandbox`).
- **Isolate Runner Dispatch Bench**: High-throughput multi-isolate batch dispatch (`https://shakyapurna.com.np/#/lab/isolate_runner_mixin/sandbox`).
- **Resumable Downloader Range Simulator**: Chunked HTTP range assembly with SQLite state persistence (`https://shakyapurna.com.np/#/lab/resumable_downloader/sandbox`).
- **Clean Feature Architecture Virtual Explorer**: Interactive tree explorer of Clean Architecture feature layers (`https://shakyapurna.com.np/#/lab/clean_feature_arch/sandbox`).

---

## 05 // Site Navigation & URL Structure

- `https://shakyapurna.com.np/` — Home overview, hero terminal, live atmospheric sky
- `https://shakyapurna.com.np/overview` — Architectural profile, technical philosophy
- `https://shakyapurna.com.np/systems` — Commercial production case studies
- `https://shakyapurna.com.np/packages` — Open-source package registry
- `https://shakyapurna.com.np/tools` — CLI developer tools & Homebrew formulas
- `https://shakyapurna.com.np/lab` — Interactive Package Lab workbench
- `https://shakyapurna.com.np/lab/:id` — Direct package workbench module
- `https://shakyapurna.com.np/resume.pdf` — Downloadable PDF resume
- `https://shakyapurna.com.np/llms.txt` — This plain-text AI specification