What’s the biggest, most well known thing you’ve ever coded?

Question: What's the biggest, most well known thing you've ever coded?
- Keywords:
  coded
Asked by ExplodingCowOnTheMoon =D to Yinka on 5 Mar 2018.
- Yinka Abejide answered on 5 Mar 2018:
  
  Great question! The biggest thing I have ever coded was determining the amount of milk a cow could have produced in 305 days even when she was milked for just 6 days only!

Question: What's the biggest, most well known thing you've ever coded?