Software that keeps the trail of the calculation, not just the result

Why we built it

It did not start with market research: our own calculation spreadsheets grew until they became unmanageable. Formulas were scattered across tabs, nobody knew which year a factor belonged to, and when we opened last period's file even we could not remember where some numbers came from.

So we put the trail of the calculation, not the calculation itself, at the centre of the product. The engine is deterministic: the same input always gives the same result. It keeps every intermediate value it uses to produce the result. Every methodology change we make is recorded with its date, because when last year's report does not match this year's, you need to be able to tell your client why.