Why I Gave WindowCalc Away: 17,700 Lines to the Trade

Before there was a company, there was WindowCalc.

I built it alone, nights and weekends. It wasn't a toy. By the end it was about 17,700 lines of Flask backend, 190 API routes and 45 database tables, plus an offline phone app that could price a job in a driveway with no signal at all.

It did a lot:

• Margin governance: A green, yellow and red stoplight against the floors each company set, with a manager's approval required below the floor.
• Design-pressure and NOA checks: A risky opening got flagged red, but the rep could always save. The field always finishes; the office corrects.
• County lookups: Owner, folio and building details pulled from South Florida property appraisers to pre-fill a job before anyone typed.
• Job chat and texting: Customer texts and job photos threaded into the quote, with internal notes kept apart.
• Proposal links: Tokenized expiring links a customer could open without a login, with views tracked.
• An offline field app: It pulled a fresh pricing bundle every fifteen minutes, queued changes while offline, and priced with the same math as the server.

It worked. Then it broke, and it broke where a dealer can't afford it to.

What Broke It

Pricing.

Manufacturers in this trade revise dealer pricing on their own schedules, every one of them differently, all year round. WindowCalc kept that pricing inside its own code. Every price change meant a code change. One application holding that many manufacturers' numbers was chasing a target that never stopped moving.

The lesson took me a while to see, and it's the most important thing WindowCalc taught me:

Pricing doesn't belong wired into the software that quotes it. It belongs outside the code, as data that can change without touching a single line of software.

That one sentence is the foundation Quote Converter Pro™ is built on.

Why Give It Away?

I could have left WindowCalc sitting in a private repository. Instead, I released it under the Unlicense, into the public domain.

Somebody in this trade can use the county lookups, or the offline sync, or the margin stoplight logic, even if they never use the whole platform.

It's free. Take it, rip it apart, use it however you like, commercially or not, whole or in pieces. No permission needed. A mention is appreciated and never required.