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ProductJun 6, 20261 min

My father scolded me over a bill. So I built an app.

arc: years of doing his bills by hand → wrong totals on real bills → the mistakes were all arithmetic → built the part a machine never gets wrong

my father is a paint contractor.

every time he finishes painting a bank branch, the owner needs a bill. material lists, work measurements, totals, all of it.

and every time, that bill was me.

he calls me, tells me the items, and i sit with ms-word typing each line one by one, adding colors to fonts, adjusting sizes, then a calculator for every single total, then export to pdf and send. i did this for years.

and many times i made calculation mistakes. a wrong total on a real bill going to a real owner. my father got the complaint and i got the scolding.

the mistakes were always in the same place. never the typing, always the arithmetic. i was doing by hand the one part a machine never gets wrong, late at night, after a phone call.

so i built the fix properly. an android app and a web app, both talking to the same database in real time. sections, work measurements, per-day rates, advances, and a one-tap PDF where the maths cannot be wrong. a bill that used to eat my whole evening now takes minutes.

honest part, my father still does not use the app himself. he still calls me. but now i open the app while he talks, and the pdf is ready before the call ends.

i did not build it for a resume. i built it because i was tired of being wrong.

the app → Site Bill Automator

#buildinpublic #sideprojects #softwareengineering #learninginpublic

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