About Nanook
Nanook is an open-source toolkit for systematic test case and test data creation. It was created to solve a common problem in software testing: maintaining consistent, reproducible test data that stays in sync with your test case specifications.
Using decision tables — XLSX spreadsheets that define input fields, their equivalence classes and the test cases — Nanook generates test data through pluggable generators and hands it to writers: JSON files by default, or any format a custom writer produces. Version 3 is written in TypeScript, ships as one ESM package and requires Node.js 22 or newer.
Nanook is used by enterprises including Deutsche Bahn for automated test data generation.
Creator & Lead
Torsten Link — Creator of Nanook, Senior Software Architect & Test Automation Lead
Torsten is an experienced software architect with deep expertise in quality assurance, test automation, and CI/CD pipeline design. He has over 11 years of Node.js and TypeScript experience and has led QA efforts on large-scale enterprise platforms — including Deutsche Bahn’s passenger information system, where he established test automation architecture across hundreds of microservices.
His background in building scalable testing infrastructure for complex distributed systems led directly to the creation of Nanook: a tool that bridges the gap between test case specification and automated test data generation.
The Company
Nanook is an open-source project by BeeBack UG (haftungsbeschränkt), based in Frankfurt am Main, Germany. BeeBack UG develops digital services and open-source tools under the xhub.io brand. Managing Director: Patrick Jerominek.
Get Involved
Nanook is released under the MIT License. Contributions are welcome.