The Lab
A collection of experiments, projects, and prototypes
2026
KnowHive
A local-first knowledge base desktop app with hybrid retrieval, an agent tool layer, long-term memory, and injection defenses — every retrieval change validated by RAGAS A/B before becoming the default.
Project highlights
- Retrieval: a unified document layer picks a chunking strategy per file type and uses parent/child blocks. Hybrid recall over vectors and FTS5 keywords, fused with RRF and reranked by a cross-encoder, then parent-block expansion restores context. Promoted to default only after RAGAS A/B showed context_precision 0.788 → 0.862. Also fixed FTS5 silently failing to tokenize Chinese, which had disabled keyword retrieval entirely (recall +0.054).
- Agent tooling: 7 knowledge-base and session-history tools on the AI SDK tool loop, with call caps and duplicate-retrieval guards so a text answer is always produced. Write operations fail closed and require human approval (HITL).
- Long-term memory: past conversations are distilled into semantic, preference, and episodic memories, retrieved by vector search or injected directly. Questions whose answer existed only in conversation history went from 0% to 100% correct.
- Refusal and injection defense: a rerank-score threshold turned unanswerable questions into correct refusals 32% → 91% of the time (4% false refusals). Spotlighting isolation cut injection success from 0.40 to 0.27. A later refactor regressed it to 0.47, caught by a self-built red-team suite before merge.
GoChatroom
Real-time chat backend in Go supporting private chat, group chat, and P2P video calling, with a React frontend on Vercel and the service on Fly.io.
Project highlights
- Goroutine-per-connection with separated read/write loops, buffered channels for non-blocking delivery, and differentiated backpressure for chat and signaling. Profiling traced a throughput ceiling to synchronous persistence inside the Hub event loop; proposed an async, sharded fix.
- Stateless JWT auth with zero DB lookups on business endpoints, Redis session management, and a custom WebRTC signaling service supporting ICE candidate queueing plus two-level recovery for signaling and media.
Travel Agent Booking System
A comprehensive booking management system designed for travel agents to track flights, hotels, and insurance payments with customer payment tracking.
2025
Sportlingo Coaching Dashboard
B2B coach dashboard for team management and analytics, enabling coaches to add users to teams, monitor individual progress, and track performance metrics.
Makeform.ai
An innovative platform that empowers users to easily design and deploy dynamic online forms using AI, enhancing productivity and user engagement.
2024
2023
Food E-commerce Platform
An online store for browsing and purchasing food products.