R&D built a commission calculator with a rounding bug

“Git is basically a backup.”— Plant Manager

Reason:

Mainly because someone built a prototype during lunch. With dark mode and no error handling.

Built by:

Miriam, a team lead

Build time:

7 evenings

Built with:

Excel macros, exposed over HTTP

Database:

an Excel file pretending to be a relational database

Authentication:

production is technically the test environment

Deployment:

kept alive by a scheduled task every 4 minutes

Responsible:

Miriam, who only knows the database

Documentation:

a Confluence page whose screenshots are all out of date

Security situation:

it emails a CSV of everything at 17:24, nightly

Future disaster:

It will stop working when Miriam's credit card expires.

Age: 248 days · originally expected to last 14 days · 1 owner so far · last meaningful change 248 days ago

Rated common mostly because: €322k per year, alive 18x longer than intended, 14% chance of becoming business critical.