When several partners share the revenue and the costs of a fleet, the monthly closing is the mome...When several partners share the revenue and the costs of a fleet, the monthly closing is the mome...
The network for creativity
Join 1.25M professional creatives like you
Connect with clients, get discovered, and run your business 100% commission-free
Creatives on Contra have earned over $150M and we are just getting started
Back to feedPost
Alan's avatar
Alan Martinez
• 14h
When several partners share the revenue and the costs of a fleet, the monthly closing is the moment where trust either holds or doesn't. The numbers were living in spreadsheets, and every closing was rebuilt by hand.
I built the system that runs it. Income and expenses per unit, shared costs split by rule, per-partner withholdings, and a partner statement with a running balance — paid and projected side by side.
The hard part isn't the arithmetic. It's what happens after a closing is saved and the underlying data moves. A customer pays an invoice three weeks late. Someone corrects an expense that was off by a couple hundred pesos. Most systems handle this by locking the period, which means the correction never makes it in, or by silently recalculating, which means nobody knows what changed.
This one does neither. A saved closing that no longer matches its source data gets flagged as out of date. Open it and you get a comparison by unit, then a hierarchical diff of what actually moved — new entries, deleted ones, modified ones with the old value struck through next to the new. You see the delta before you accept it, and recalculating is one deliberate action.
That's the whole design principle: when money is split between people, the system's job isn't to be right. It's to show its work.
The link below is a working recreation of the closing flow with fictional company and data. Try the closing flagged out of date and walk the diff.
https://claude.ai/code/artifact/c212bbe9-7c89-44ce-a80a-50c174d7b9ae?via=auto_preview
AI DevelopmentDesign SystemsProduct DesignNext.jsSupabaseTypeScript
Post image
Back to feed
The network for creativity
Join 1.25M professional creatives like you
Connect with clients, get discovered, and run your business 100% commission-free
Creatives on Contra have earned over $150M and we are just getting started