Direct contractEU B2B e-invoicing · 2025 · Lead engineermyfiletracker.com
MyFileTracker
A prototype taken to a Peppol-compliant invoicing platform in a 13-day fixed-price engagement.
MyFileTracker is a direct Upwork contract: a Peppol-compliant EU e-invoicing platform taken from prototype to a validated, audited production system in a 13-day fixed-price engagement, the same prototype-to-production jump The SyncFlow's Vibe Code to Production service now formalizes.
- Direct
- Attribution
- 13 days
- Scope
- 5.0
- Status
13 days, $1,010 fixed price, 5.0 rating, public on Upwork, 12–25 May 2025.
The problem
EU B2B e-invoicing rules turned invoice formatting into a compliance requirement. The client arrived holding a prototype that had never been run against a real document, and needed a platform that could accept documents, validate them against the Peppol standard, and keep an auditable record of every state change.
Compliance work is unforgiving in a way most prototype code is not built for: a document that is nearly right is rejected, and a rejected invoice is an unpaid one. The two-week window was spent turning something that worked in principle into something that could survive a real document.
Constraints
The conditions the solution had to survive, not a wish list.
- Regulatory deadline
- The standard is fixed and external. There was no version of the build where the format was negotiable.
- Short window
- Delivered inside a two-week fixed-price contract.
- Audit requirements
- Every document needed traceable status history, not just a current state.
- Multi-tenant
- Organisations share the platform and must never see one another’s documents.
The approach
In plain English, before the architecture.
Validation was rebuilt as the core of the product rather than a check at the edge. Documents are parsed into a structured representation first, then validated against the standard, so failures are specific and fixable instead of a generic rejection.
Status is modelled as a sequence of recorded transitions, which makes the audit trail a by-product of how the system works rather than a separate log to keep in sync.
Architecture
The decisions that mattered, and why they were made that way.
- 01
Structured invoice parsing
Uploaded documents are parsed into a typed intermediate representation before validation, so errors point at a field rather than a file.
- 02
Per-document status tracking
Each document carries an append-only history of state changes, giving a complete audit trail without a parallel logging system.
- 03
Organisation-level isolation
Multi-tenant architecture with role-based access control and data isolation enforced at the organisation boundary.
- 04
Firebase-backed storage and auth
Document storage, authentication and access rules on Firebase, keeping the infrastructure small enough for one engineer to own end to end.
Outcome
Delivered against the Peppol standard in 13 days from a standing start, with the client’s own account: “you ask, he delivers, and always above expectations.”
Closed at a 5.0 rating on a fixed-price contract, with the audit trail and organisation isolation holding as the platform went live.
Stack
- Next.js
- React
- TypeScript
- Node.js
- Firebase
Timeline
12 to 25 May 2025, fixed price
Contract value
$1,010 fixed price
Tell us what you can’t staff.
Twenty minutes. No deck, no discovery sequence. If we are the wrong fit we will say so on the call and point you somewhere better.