# I Shipped the First Real Stage of My Fanfiction Taste Engine, and It Isn't What I Originally Planned
A few weeks ago I wrote about Siagnos , a personal taste engine for fanfiction that learns from reading behavior instead of matching tags. I was three stages in: scraper done, schema designed, embeddings working as a proof of concept. Then I got a two-week internship window to build something deployable, and I made a call. Instead of pushing Siagnos forward stage by stage, I built Opsis : a scoped-down, content-based recommender that answers one specific question. Given a fic, what else in a real, collected corpus is closest to it in content? Opsis doesn't do taste modeling. It doesn't touch my reading behavior at all. It's the layer underneath that, and it's live right now. Why not just keep building Siagnos directly Two weeks isn't enough time to get a reading tracker, a feature pipeline, and a trained preference model all working end to end. It is enough time to take the scraper and schema I already had and turn them into something real: a working recommender, deployed, with a UI, that someone else can actually use today. So I scoped down on purpose. No personal taste model yet. No behavior tracking yet. Just: can I take one fic and find genuinely similar ones, from AO3 metadata alone, using content instead of tags? What Opsis actually does Scrapes AO3 metadata under conditions the OTW Communications Committee confirmed were acceptable before I collected anything: one persistent session, randomized delays, capped retries Cleans and validates the raw data, log-and-skip instead of all-or-nothing, so one malformed row doesn't take down a 7,000-fic load Normalizes everything into PostgreSQL: fics, six lookup tables, six join tables, idempotent upserts so re-running the loader is always safe Embeds every fic's summary with sentence-transformers/all-MiniLM-L6-v2 Ranks candidates with a blended score: 0.70 embedding cosine similarity, 0.15 fandom overlap, 0.10 relationship overlap, 0.05 popularity If you submit a fic that isn't in the database yet, Opsis scrapes it, cle