Domenico Perroni

Payroll checks before the payslips go out

Eleven checks on Italian payslips under the retail and services contract (CCNL Terziario): minimum pay, seniority steps, INPS contributions, severance accrual, holidays, the F24 tax payment, master-data changes nobody declared, 13th and 14th month accruals. Plus what the November 2026 pay rise costs each client.

• Finds all 32 planted errors with no false alarms; a statistical anomaly detector on the same data finds about a third.
• Three twins, one answer: Python, a live-formula sheet (496 checks) and a browser tool (1,952 values) agree, and files never leave the computer.
• Sources on every rule, and a test that keeps the one error no check can see on record.

In Italian.

Vimeo: where the next dollar comes from

An outside-in case from Vimeo's SEC filings. Self-Serve has lost subscribers for three years while price held revenue up; Enterprise pays about 120 times more per account. The bet: route the Self-Serve teams that already look like Enterprise buyers to sales, and test it before hiring for it.

• Revenue split into volume and price for every category, from figures traced to each filing.
• $2.2M net present value at 1 extra upgrade per 100 accounts a year; it breaks even at 0.68%.
• A test sized against the data: of four designs only one can see the break-even on 22,558 accounts, and the decision rule's error rates are measured, not assumed.

Ready for the EU Pay Transparency Directive?

A dry run of Directive (EU) 2023/970 for an employer in four countries, 3,443 workers, delivered as a consulting team would: what each entity owes and when, the seven reporting items, the joint pay assessment screen, and a plan for the next 90 days.

• A live Excel model reconciled with pandas on 460 figures, recalculated in LibreOffice on every change.
• A board briefing and a readiness checklist, with a register of every legal source.
• Clear about its limits: synthetic data, and what each Member State's transposition can still change.