The Billion-Dollar Mistake and Other Software Horror Stories

Intriguing Stories in Computer Science

The Billion-Dollar Mistake and Other Software Horror Stories

A curated list of intriguing stories from computer science history, from catastrophic bugs like the Ariane 5 explosion and the Therac-25 radiation overdoses to legendary design philosophies like Unix pipes and Erlang's 'let it crash'. The author, reflecting on age, shares both cautionary tales and enduring principles that shaped software development.

Tony Hoare’s “billion-dollar mistake” — inventing the null reference.
  1. anArbitraryOne

    I disagree with the author about Black Lives Matter and abolishing ICE (more like abolishing the leaders who enable ICE to do terrible things - maybe there's some common ground there)

  2. Zecc

    1947: Harvard engineers working on the Mark II computer find a moth stuck to one of the relays. They tape it to a logbook and write "First actual case of a bug being found" and introduce the words 'bug' and 'debug' in the context of programming.

    https://americanhistory.si.edu/collections/object/nmah_33466...

  3. potatium

    Not sure if it's more of an urban legend, but the old story went that one (or two?) Soviet Mars probes in the 80s went wildly off course because of the typo in their nav software, allegedly written in Fortran. A comma was misplaced for a dot.

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2026-08-17