Projects

Master's thesis — a multimodal virtual try-on system combining lightweight YOLO classification with LoRA fine-tuned diffusion models and LLM agent control. Built on limited resources: two 16GB Tencent Cloud free-tier GPU servers (one for diffusion, one for LLM) + Raspberry Pi 5. Published at IVCNZ 2025. 94.2% accuracy, FID 28.5, completed 6 months early.

Garment factories needed real-time production tracking across multiple sites. 6-person team. I owned all Android clients (phone/tablet/shop-floor), wrote ~1/4 of backend (3 Spring Cloud modules), built hardware communication programs (scales via serial-to-WebSocket bridge, conveyors, washers), and helped with Vue.js frontend when needed. 10+ factory sites, 30%+ efficiency gain, hundreds of daily workers.

Internal messaging tool for 5,000 employees had chronic stability issues. Legacy C++ core was unmaintainable — migration had to happen without downtime or message loss. Incremental migration to Spring Cloud + Kotlin Android client, keeping the NDK transport layer for low-latency delivery while replacing everything around it. 90%+ defect elimination, <200ms latency, 500K+ daily messages, ran stable for 10 years.

IoT device management platform for smart switches and gateways. Android app for device discovery/binding/control, embedded Linux gateway firmware handling Zigbee/WiFi protocols, Spring Cloud backend for registration, grouping, and remote monitoring. 7-year product line.

24/7 smart self-service library cabinet for schools. Cabinet-side Android host controls 10+ hardware peripherals via UART/RS485 and GPIO: electromagnetic locks, UV-C lamps, LED strips, RFID high-frequency antennas, face recognition camera, card reader, receipt printer, door sensors. Separate borrower Android app with face/QR auth for <3s transactions. Admin backend handles book catalog, locker init, and cabinet API orchestration. After the other Android dev resigned, handled escalation and scope rebalancing to keep delivery on track.

Gateway-centric breaker control platform: non-networked circuit breakers connect via RS232 serial bus to Android gateway. Telemetry collection, remote open/close control, local alerting, and cloud reporting for multi-site monitoring.

Offline-first Android GIS app for forest rangers in zero-signal areas. ArcGIS Runtime SDK for map rendering, GIS annotation, and area calculation. Key challenges: extremely weak GPS in dense forest (up to 30s between fixes), coordinate system conversion across WGS-84 (offline Google tiles), BD-09 (Baidu online), and GCJ-02 (national standard) with auto-detection on map source change. Deferred sync for fire/pest/flood/risk reporting. Deployed for local forestry dept with tens of field rangers. Built solo over 1 year.

Freelance Android project completed in ~1 month of spare time. Built core crypto trading features — real-time market (WebSocket), wallet, exchange, recharge — on an existing MVVM codebase. Deployed via website distribution (not app stores). Focused on secure comms: HTTPS, request signing, parameter encryption.

Smart power platform for factories and buildings: onboard gateways, switches, and meters; monitor per-load electrical parameters; remote control and alarm policies. 15% energy saving, sub-second alarm, 99.9% data collection rate.

Smart face recognition attendance system for schools with real-time parent notifications. 99%+ recognition accuracy, sub-second response, liveness detection, deployed across multiple schools.

Large-scale digital signage platform with management console and Android screen clients. MQTT broadcast for campaign task distribution, device grouping, scheduled playback, and remote publishing for elevator, in-store, and public displays.

High-secrecy banknote paper mill on-site integration. Air-gapped environment with no internet access — offline laptops for data format analysis, in-plant testing, and external development cycles. Each site visit required ~1 week advance approval.

Purchased a complete service robot with built-in Android SDK (navigation, LiDAR SLAM, face recognition, voice interaction exposed as API calls). 4-person team built upper-layer features: product introduction, ArcSoft face recognition check-in, iFlytek voice-guided tours, knowledge base. My role: Android interaction interface and robot SDK feature integration. Deployed at a building materials & decoration client exhibition hall (store fit-outs for brands like Apple, Huawei).

End-to-end AI platform for image classification: category management, data annotation, model training (YOLOv4/ResNet/MobileNetV3), evaluation with release-gate criteria, and inference serving. Designed as reusable workflow for multiple visual classification domains.

The company's earliest product — a live streaming chat room platform built during the start-up phase before pivoting to IoT. 8-person team. I built: ASP.NET/DNN monolithic admin backend (no front/back separation), a Node.js + Socket.IO web chat room with HTML5 M3U8 video playback, and the Android client. Also contributed to the C++ server core. Server was rewritten multiple times. Company exited this business in 2015.

Enterprise patent document management: .NET Framework 2.0 Windows desktop app with Lucene.NET 2.9 full-text search. 10,000+ patent records, Excel batch processing, sub-2s search response for 50+ daily research users.

Led Android performance optimization across IM client and Smart Gateway apps over 8 years. Six optimization domains: memory (LeakCanary, Heap Dump, OOM prevention), CPU (hotspot analysis, thread scheduling), UI fluency (RecyclerView, Jank reduction), cold-start, APK size (200MB+ down to 80-90MB, 55% reduction via R8/ProGuard), and stability (OOM/ANR/Crash governance). Built data-driven profiling workflows.

Experimental predictive maintenance exploration using factory-provided textile equipment records. Applied Spark MLlib Random Forest on historical maintenance logs — limited data constrained accuracy, but gained hands-on experience with Spark MLlib ecosystem, feature engineering pipelines, and industrial data modeling. Did not progress to production deployment.

In-house Android hotfix framework supporting dex patching and resource hotfix on Android 5+. Native .so patching was not supported. After years of practice, led the decision to retire the system in favor of staged rollout + feature flags, achieving simpler architecture and lower maintenance costs.

Prison visitation system. Android terminal app for inmate-side video visitation (prisons prohibit personal phones — app runs on facility-managed devices). Admin backend for booking approval, time slot allocation, and visit policy. WebRTC audio-video sessions with lifecycle management (create, join, leave, timeout) and compliance recording. Face recognition access control for visitor verification.

Customer-site vehicle weigh-in system: read stable weight from entrance scales, raise overload warnings, and interlock with barrier/signal hardware. Serial/device integration under field constraints.