Leading zeros and exponents in identifiers

Numbers that are really strings, met in the first month and never forgotten.

Three fixes in one day, all the same bug wearing different clothes. An identifier came out in exponent form. Another lost precision past fifteen digits. A third lost its leading zero. The spreadsheet had decided these were numbers; they were codes.

The fix was a rule, not a patch, and every ETL I built afterwards started with it.

The rule

Anything that identifies something is a string until proven otherwise, and the type is decided at the column, not the cell.

Client engagement, 2021 to 2026. Names, identifiers and internals are generalised.