The ecology of Earth’s first large organisms is an unsolved problem in palaeontology. This experience report discusses the determination of which ecosystems could have been feasible, by considering the biological feedbacks within them. Haskell was used to model the ecosystems for these first large organisms – the Ediacara biota. For verification of the results, the statistical language R was used. Neither Haskell nor R would have been sufficient for this work – Haskell’s libraries for statistics are weak, while R lacks the structure for expressing algorithms in a maintainable manner. This work is the first to quantify all feedback loops in an ecosystem, and has generated considerable interest from both the ecological and palaeontological communities.