John Stephens · Everything Windows and Doors
By day, windows & doors. By night, software.
This is my home base. Everything I write about AI, apps and the projects I build after hours, plus the side projects themselves.
Now building: Retrostack Software
Pick a pane. Every pane is a topic.
Fresh off the night shift
Latest writing
Can AI Replace Your Accountant? (I Used a Ton of AI to Find Out)
The goal isn't to replace the accountant. It's to stop paying the accountant to type.
AI & AutomationWhy Most Window & Door Tech Solves the Wrong Half of the Job
Drawing the floor plan takes eight minutes. Getting through the paperwork between the tape measure and the factory floor takes eight days.
AI & AutomationWhy Doesn't Everyone Just Build Their Own House? (The DIY Tech Trap)
Having the tool and knowing how to make it run a business are two very different things.
AI & Automation"Just Let AI Run My Ads" Is How You Burn Cash Fast
AI can make your ads better. It can't run them for you, and it can't fix a bad business. A marketing director who also writes software explains where AI helps and where it burns money.
AI & Automation6 Questions to Ask Before You Buy Any AI App (Because Vibe Coding Will Bite You in the Ass)
An AI-built app looks great in the office and falls apart in the field. Six questions every window and door company should ask before buying "AI-powered" software.
AI & AutomationThe Marketing Engineer: When Marketing Becomes a Programming Problem
Marketing used to mean picking a segment and guessing. AI turns it into something dealers build, not just something they write.
Apps & SoftwareThe Shiny Object Trap: Everybody Loses Their Mind Over New AI Software Every Three Weeks. Here's What's Actually Worth It.
Most new AI tools are parlor tricks. A few actually changed how business gets done. Here's how to tell the difference, from a guy who sells windows and writes software.
Four panes, one blog
Pick a topic
Built after hours
Side projects
The apps are grown up now and have their own homes. The experiments live here.
Aperture
Coming soonCapture every opening at the house.
aperturemeasure.com ↗
Eyewall
Coming soonDraw the house. Mark every opening.
eyewallapp.com ↗
Quote Converter Pro
Coming soonTurn the job into a clean, branded quote.
quoteconverterpro.com ↗WindowCalc
My first full quoting platform, built alone on nights and weekends. 17,700 lines, then released into the public domain.
Manufacturer spec hubs
Free, searchable hubs of public product specs and approval links, one per manufacturer. Nobody asked for them. I built them anyway.
Dealer toolkit
Eight calculators for window and door folks: margin and markup, financing, job profit, commission, opening sizes, glass weight and more.
Focus Bridge
A “where was I?” desktop app for people juggling too many projects. One box to catch the thought, then back to work.
My software company
Retrostack Software
The apps grew up and got their own company. Retrostack builds Aperture, Eyewall and Quote Converter Pro, and it’s owned by Everything Windows and Doors.
Who’s behind this
Hey, I’m John
I started in this trade at nineteen, on a ladder, cutting shims. Since then I’ve worked nearly every seat an impact window and door business has. At night I write the software I wish we’d had the whole time.
This site is where all of it lands: the writing, the experiments and the companies.