Litprofit Project Calculator
- Product design
- Web app
- Offline-first data
- Encrypted access
The whole costing workbook — labour, subcontractors, travel, materials, logistics — with every formula unchanged
The problem
Every ship repair job was costed in a spreadsheet workbook -- nine sheets of labour, subcontractors, travel, materials and logistics -- and each one lived in whoever had opened it last. There was no way to see the whole book at once, and a spreadsheet sent round by email becomes one copy per person within a week.
Our solution
The workbook as a web app, with every formula unchanged, restyled onto the site's own tokens and built in three languages. A portfolio tab puts every project side by side and totals the company on a revenue-weighted margin, so a small job at 90% cannot drag the company figure around. The period filter is an overlap test rather than "started within", because the question anyone actually asks is what ran during February. Closing a project makes it genuinely read-only -- the inputs are disabled, not greyed -- and the CSV exports carry a BOM and CRLF endings so Excel opens them correctly, verified at byte level. Data stays in the browser by default; Postgres is optional and off unless configured. The published page is encrypted rather than gated: both the username and the password feed the key derivation, so without them there is nothing in the file to read.
What it took
The published page holds ciphertext; both the username and the password feed the key derivation
Figures stay in the browser; Postgres is optional and inert until it is configured
The work
Same shape of problem on your side?
Thirty minutes, no deck, and a reply within one working day.
“You will be talking to me, not to an account manager. I scope the work and I am on the build.”