As a European programmer, the comma-period-decimal struggle is real.

Most higher level programming languages don’t accept commas, so decimals are started by a period, and thousands can sometimes (varies by language) be separated by underscores.

For example, these are all valid number notation:

1.00
0.000001
1_000.00
1_000_000
1_0_0_0_0_0_0.0_0

If you use the final one frequently, though, your employment may experience a period too.