Codebase RAG
Delivered a Workers + D1 retrieval pipeline over 1.2M LOC that serves accurate code answers in 420ms p95, boosting incident triage resolution by 37%.
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Personal notes / Technical blog
Roy Zhu's technical notebook.
I'm Roy Zhu. This is my personal site and technical blog, where I keep notes on architecture, developer experience, AI-assisted workflows, and the practical details behind building software.
Featured Projects
CoPal
Launched a Playwright + Workers co-browsing assistant that cuts enterprise onboarding time by 45% through scripted product walkthroughs.
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Recent Posts
Concurrency in Local-First AI: Making SQLite Multi-Agent Safe
Updated: at 08:00 AMHow to fix SQLite database locks when multiple AI agents write to memory simultaneously, using WAL mode, threading.local, and application-layer RLocks.
Graph Traversal Without a Graph Database: BFS in Pure Python
Updated: at 07:00 AMWhy Neo4j is overkill for a personal AI agent's memory, and how to implement fast, multi-hop context retrieval using BFS in pure Python over SQLite.
Building a Deduplication Pipeline for Local Knowledge Graphs
Updated: at 06:00 AMWhy LLM extraction fails at knowledge graphs, and how a cascade of exact aliases, embeddings, and string fallback keeps local SQLite graphs clean.
Setting Up a Python Project Skeleton That Scales
Published: at 09:00 AMHow membox chose its libraries, organized its modules, and used typing.Protocol to keep the core dependency-free while staying testable and extensible.