半開Let flowers bloom halfway; leave room for the rest.https://halfopen.dev/en/2026-10-03T00:00:00+08:00半開Building hybrid RAG retrieval with keywords, vectors and traceable citationshttps://halfopen.dev/en/writing/rag-hybrid-search/2026-10-03T00:00:00+08:00Start with a keyword baseline, then add real vector retrieval, rank fusion, access and revision checks, evidence budgets and citation validation using a synthetic example.From software testing to AI application development: choosing and validating projectshttps://halfopen.dev/en/writing/testing-to-ai-development/2026-10-03T00:00:00+08:00Turn API testing, test data and failure analysis into a complete AI project, with repeatable checks for success, failure and recovery and clear evidence boundaries.