Projects

Problems live in an editable category tree, every attempt is rated by familiarity, which determine the schedule of when to re-practice.

• Cross-service SSO — signs in with the roger.tw account through a shared session token: no second login, access granted per account
• Spaced re-practice engine — rate each attempt by familiarity (0–3), set an interval per familiarity, and get a prioritized due list instead of a to-do list
• Editor-grade UI — drag-and-drop across categories, inline structure editing, a live table of contents, one-click LeetCode autofill
• Production deployment — containerized dev/prod on my own server behind Nginx/TLS, with Arcjet bot & rate-limit protection and PostHog analytics

Real-time safety monitoring for high-density venues (stadiums, metro stations), built in 30 hours as hackathon lead: edge AI detects crowd conflicts, the cloud generates the incident report for security staff.

• Built edge-to-cloud pipeline with MQTT protocol for low-latency event transmission from ICAM-540 to AWS IoT Core
• Architected fully serverless infrastructure using Lambda, AppSync GraphQL, and DynamoDB with real-time subscription updates
• Integrated Amazon Bedrock Claude 3.7 Sonnet for automated narrative generation from conflict detection frames

Tower defense game fully synthesized on FPGA hardware with VGA output and mouse input. Demonstrates end-to-end digital circuit design from game logic to peripheral interfaces.

• Built Verilog game engine with multiple FSMs controlling character logic, resource generation, and state transitions
• Solved timing bottlenecks via parallel rendering pipelines and custom sprite compression within FPGA constraints

Real-time strategy battle game with local AI and online PvP, a character roster with unique abilities, elixir-based resource management, and a dynamic combat system.

• Built real-time multiplayer with Boost.ASIO TCP/IP sync and synchronized game state across clients
• Developed diverse characters with varied skills and gameplay using object-oriented inheritance hierarchy
• Implemented physics engine with grid-based pathfinding and pixel-perfect collision detection