The $440M software error at Knight Capital (2019)
The OP details how poor software engineering practices brought down a 1.4B market marker with 1400 employees in 2012.Some of the issues mentioned include:  - Keeping synthetic test data generation as part of a production build.
  - Keeping dead code for years.
  - Re-purposing a feature flag.
  - Refactoring without regression tests.
  - Manual deployments without peer reviews. They forgot to update one of their servers with the new code.
  - Automated alerts sent via email were ignored.
  - Rolled back to a version of the code running on the server they forgot to update, making things worse.
  - Rushing out a release without proper software engineering hygiene.

The article suggests improvements that could have prevented the chain of events.For those here who are in HFT circles, have things improved after the Knight Capital Group debacle?edit: formatting