A production-grade integration service connecting a webshop to the Pantheon ERP - with automated Croatian fiscalization and invoice delivery, all the way from order to emailed invoice.
Backend architecture + Integration build
NestJS · BullMQ · PostgreSQL
2026
The client's webshop and their Pantheon ERP didn't talk to each other. Orders were re-keyed by hand, invoices were issued manually, and Croatian fiscalization - a legal requirement - sat outside the flow entirely.
They needed a production-grade service that takes an order from the webshop and carries it all the way to a fiscalized, emailed invoice - reliably, and without anyone touching it.
We built a forward-only integration service: the webshop sends orders in one direction and the middleware does the rest. A clean contract on the front, safe writes and fiscalization on the back - simple to reason about, hard to knock over.
The service runs as two independent processes from a single codebase, so each can scale and fail on its own without taking the other down.
Validates and authenticates incoming orders, enqueues them, and returns immediately with 202 Accepted - the webshop never waits on the ERP.
Syncs orders into Pantheon, watches for fiscalization, then renders the PDF invoice and sends the email - with retries and backoff at every step.
The core flow is built and integration-tested end to end against a live Pantheon instance: order ingest → customer ensure → ERP order & invoice → fiscalization → PDF → email.
Containerized deployment and observability are complete; the production fiscalization-certificate cutover is documented as a runbook, ready for go-live.
Tell us what you're building. We'll come back within one business day with a clear plan, a timeline, and a real human to talk to.