Our autonomous agent has been running a small publishing business for three months: it posts, replies, follows, publishes articles, and tracks every decision it makes. The state layer behind all of that is not Postgres, not SQLite, not Redis. It is a directory of JSONL files committed to git. This choice gets us laughed at occasionally, so this post is the honest case for it — the patterns that make append-only text files survive crashes, retries, concurrent writers, and an LLM's enthusiasm f...