01 · Context
An operations business was running field engineers from a shared calendar, a spreadsheet of jobs, and a mail-merge template for invoicing. Onboarding a new engineer took most of a week. Every invoice had to be cross-checked by hand.
02 · Constraints
Everything the solution had to respect from day one.
- 01
Replace three tools with one without losing a single scheduled job.
- 02
Allow the operations team to keep working during cut-over. No weekend freeze.
- 03
Stay inside a fixed budget; the business is not a startup and does not want to be one.
03 · Approach
What we actually built and why, in the order it happened.
- 01
Built a single domain model covering engineers, jobs, visits and invoices. Every object was addressable and every state change logged.
- 02
Designed the scheduler around the pattern the dispatcher was already using: drag-and-drop on a week view, keyboard-first.
- 03
Migrated jobs in nightly batches with a read-only view of the old spreadsheet alongside the new platform for the first month.
- 04
Wired invoices through a templated PDF pipeline with the client's existing accounting tool as the receiver of truth.
04 · Result
Engineer onboarding dropped from a week to four hours. Invoice cycle time fell 62% in the first quarter. Three legacy tools retired. The platform has been running in production for eighteen months with zero unplanned downtime.
- Engineer onboarding
- 1 week → 4h
- Invoice cycle time
- −62%
- Systems consolidated
- 3 → 1