The Worst Typo I Ever Made
Why Hacker News recommends it
Shared in outage and accidental-deletion threads as a relatable, well-told horror story.
What it is
Tom Scott recounts the worst typo he ever made, a subtle mistake in code with destructive consequences at a previous job. It is a cautionary tale about irreversible operations.
Recommended by 2 HN commenters across 2 different months, 2020 to 2026.
What Hacker News said
Recommends rococosbasilisk · 2020-08 · on “The “Oh Shoot” Moment”
Tom Scott has a great video on his "Oh Shoot" moment ( [this video] ). Thinking back on the times I've had code exist nowhere else but the clipboard...
Recommends sneela · 2026-07 · on “List of Humorous Units of Measurement”
The good ol' Ohnosecond: > An "ohnosecond" is the second after one makes a terrible mistake, such as deleting the wrong file or sending a text message to the wrong person, where the person in question can do nothing but say "oh no". The term is believed to originate from Elizabeth Powell Crowe's 1993 novel, The Electronic Traveler. Reminds me (and probably a lot of devs) of a time when I deployed something breaking to production many years ago :), of course I didn't know it would break production beforehand. Recently, I accidentally deleted my entire shell history which caused me quite a bit of slowdown for some time. I'm quite used to modifying complicated commands with Ctrl+R and fzf; the
Cites auroranil · 2020-10 · on “We deleted the production database by accident”
Tom Scott made a mistake with a similar outcome as this article, but with an SQL query that is much more subtle than DROP. [this video] By all means, find ways to fool-proof the architecture. But be prepared for scenarios where some destructive action happens to a production database.
Cites Sophira · 2021-10 · on “Facebook-owned sites were down”
Somebody just had their very own "onosecond". [this video] The video is one that Tom Scott published in June 2020 about the worst typo he ever made in one of his prior jobs, and while the Facebook mistake is almost certainly not going to be anything irrecoverable like this one, you can bet that Facebook pride themselves on being available all the time.