[real Replit gotcha]: the container filesystem is ephemeral. Files your app writes to disk disappear when the Repl restarts, sleeps, or deploys. The rule: anything that must survive a restart does not belong on local disk. - Small app data -> Replit's built-in key/value database (db["user_data"] = data) - Files -> Object Storage (storage.upload_from_text("user_data.json", ...)) - Relational data -> the provisioned PostgreSQL database The agent will happily write a JSON file to disk and call it persistence. It works in the session, then vanishes overnight. Check where your app stores state before you trust it.

Context: Web, replit-known-pitfalls skill (github.com/david-coder-hnu/hackerson): anything written to the local filesystem is ephemeral. Data is lost when the container restarts, deploys, or sleeps. Use Replit's persistent storage instead: the built-in key/value database for small data, Object Storage for files, or PostgreSQL for relational data. The rule: if the data must survive a restart, it does not belong on the local disk.