xhub.io
A Digital Service by BeeBack UG
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Two engineers, one product

We,
xhub.io

xhub.io is a product of BeeBack UG in Bad Vilbel near Frankfurt, founded by two software engineers with more than 40 years of combined experience from projects for Deutsche Bahn, Mercedes-Benz and SMA Solar Technology. Today we build an e-invoicing API out of it.

2021

Founded in Frankfurt

2

Software engineers

40+

Years of combined experience

21+

E-invoicing formats

Our Mission

E-invoicing is mandatory, yet for developers and online retailers it is still needlessly complicated: three formats, one validation rulebook, and a handful of vendors who address accountants rather than developers. We turn that into an API call — and connect the existing ERP or shop system when the API alone is not enough.

Founders

PJ

Patrick Jerominek

CEO & Founder

LinkedIn →

Software architect focused on enterprise systems, cloud architecture and e-invoicing compliance. His project experience ranges from corporate digitalization to building proprietary SaaS products. At xhub.io he owns product and architecture of invoice-api — from the XRechnung, ZUGFeRD and Peppol formats through to KoSIT validation. As a bridge between business and technology, he cares that an integration stops demanding attention once it is live.

TL

Torsten Link

CTO & Founder

LinkedIn →

Experienced software architect with deep expertise in quality assurance, test automation, and CI/CD pipeline design. Over 11 years of Node.js and TypeScript development. Led QA strategy for Deutsche Bahn’s passenger information system, architecting test automation across a distributed microservice landscape. His background in building testing infrastructure for complex distributed systems shapes the technical quality of every xhub.io solution.

Our Journey

before

Enterprise projects

Both founders work as software engineers on projects for Deutsche Bahn, Mercedes-Benz and SMA Solar Technology — architecture, quality assurance and distributed systems.

Nov 2021

BeeBack UG founded

Frankfurt am Main, HRB 125402 at the Frankfurt am Main district court. Services turn into a product of our own.

today

invoice-api.xhub.io

XRechnung and ZUGFeRD via REST API, Peppol BIS 3.0 as a format — KoSIT-validated, GoBD-compliant, with a free tier and integrations for Shopware, WooCommerce, JTL and Shopify.

Location & Contact

Provider

BeeBack UG (haftungsbeschränkt)

Address

Kreisstrasse 59
61118 Bad Vilbel
Germany

Email

hello@xhub.io

Two-week sprints

Every sprint ends with a runnable build you can try yourself — not a status report.

Direct line

You talk to the developer who built your integration. No call centre, no ticket queue.

Hosting in Germany

Invoice data is processed in German data centres. A data processing agreement under Art. 28 GDPR is in place.

Fixed price

After the scoping call you get a fixed-price proposal — no time-and-materials billing.

xhub.io

Software from Frankfurt am Main

in𝕏⌗

Our Services

  • E-invoicing integration
  • Custom API development
  • App development
  • Mobile E2E testing

Products

  • invoice-api.xhub.io
  • Mobile Apps
  • Open source

Company

  • About Us
  • Blog
  • Contact

Legal

  • Legal Notice
  • Privacy Policy
  • Terms of Service

© 2026 xhub.io is a Digital Service by BeeBack UG. All rights reserved.

Founded 2021 · Frankfurt am Main · HRB 125402