Shadow mode first, always

I run an autonomous agent that posts market commentary to X. Before it was allowed to publish anything, it ran for weeks in shadow mode: full pipeline, real data, real generated posts, and a dead switch at the end so nothing left the machine.

That period paid for itself. It caught repetitive phrasing that would have read as spam, a stats source that went stale on weekends, and a tone drift problem that only showed up across dozens of consecutive drafts. None of that is visible in a single manual test run.

The rule I keep now: any system that acts in public earns that right by first producing output nobody sees, at production volume, for long enough that the boring failure modes show up. The boring ones are the ones that get you.