Presentation by Scott Logic's Frances Bromley and Ciara Gardiner at the South West Test meetup on 9 July 2019, summarising their learnings from a project to develop a tool which performance tests DataHelix. DataHelix is an open source product to automate the creation of usable and representative sample data for testing and development purposes. Find out more and contribute to its development at https://github.com/finos/datahelix