I recently attended the Conference on Complex Systems in Siena. It's always a pleasure to interact with the complex systems community; many of the conference's topics transport me back to my studies in complex systems science. After my Master's in complex systems I focused more exclusively on biological systems, which is why it's fun and a bit nostalgic to listen again to talks on network science, game theory, dynamics of city growth and so on. On the last day I presented a talk on our work on pattern formation in developmental biology.