Invoicing and customs systems · Build
Invoices you can show years later exactly as issued
Each invoice is stored at the moment of issue, so later template edits can’t change it. On a customs system we checked 50,000 invoices, and none had changed.
EngagementHourly · remote
Hours9–18 CET · 4 h overlap
StackNode.js · PostgreSQL · immutable HTML snapshots
Proof3 case studies
The service in 4 parts
01 · Who it’s for
Any business or authority that may be asked, years from now, to show an invoice exactly as it was issued.
02 · What we’ve built
- Customs invoicing that renders each invoice once, at the moment of issue, and stores it as immutable HTML. We validated it on 50,000 invoices, and none changed after issue.Case study 11 →
- Invoicing, payments and a supplier ledger with accounting export, as part of a construction ERP that runs alongside SAP.Case study 16 →
- On a US marketplace, the daily renewal job downgrades a listing more than seven days late, updates its invoice and re-indexes the record, by the same rule for every account.Case study 07 →
03 · How we work
01 · TEMPLATE AND INVOICE KEPT APARTThe template keeps changing while issued invoices stay as they were. Because each invoice is stored already rendered, a later bug in the rendering code can’t change it either.
02 · TEMPLATE VERSIONSOn a new system we would also record which template version produced each invoice, and who changed the template and when. The customs system froze invoices but never versioned its templates, and that is the gap we would close first.
04 · Stack
Node.jsPostgreSQLimmutable HTML snapshotsNestJSSAP
Proof
Where we’ve done this before
Case study 11 · Identity3 domainsCustoms invoicing that renders each invoice once, at the moment of issue, and stores it as immutable HTML. We validated it on 50,000 invoices, and none changed after issue.Read the case study →Case study 16 · Business systems150,000Invoicing, payments and a supplier ledger with accounting export, as part of a construction ERP that runs alongside SAP.Read the case study →Case study 07 · Marketplace6 jobsOn a US marketplace, the daily renewal job downgrades a listing more than seven days late, updates its invoice and re-indexes the record, by the same rule for every account.Read the case study →
FAQ
Questions about this service
Because then every change to the rendering code would also change every old invoice, and nothing would raise an error.
With a new document. The invoice being corrected is never edited.
Yes. The construction ERP exchanged customer, order, invoice, stock and finance data with SAP, which stayed the system everything starts from.
Next step
Describe the problem and we’ll come back with three options.
The first call takes 30 minutes, and you’re under no obligation.