AlphaLane offers: transcript

This is the offer calculator we built for AlphaLane. It replaced a ten-year-old Excel workbook with almost two hundred thousand formulas.

A seller fills in the car, the client and the services, and the app calculates the lease and the full payment schedule.

One click gives a bilingual offer PDF, and every offer lands in a register the whole team can search.

It went live in September, five weeks after the build began. The hard part was being exact.

Parity tests check the client's own control cells, and twenty-four real offers match the workbook to the cent.

Every contract cell, all two thousand two hundred and thirty-eight, is recomputed independently, so a bug can't hide behind a matching total.

Any number on the screen has a 'How calculated?' trace, step by step, back to its inputs.

Offer PDFs are rendered on the server as true A4 pages, and stored in private Azure storage with shared keys turned off.

There's no AI in the arithmetic. Every euro comes from deterministic code.

Behind it are about seventeen hundred test cases and twelve monitoring alerts.

AlphaLane offers: exact to the cent.