Slides for the talk I've presented at WC Roma 2017 (https://2017.rome.wordcamp.org/). "Because you can’t always start from scratch. Modern Tribe took on this impervious task head-on. In this speech I share the knowledge the team working on “The Events Calendar” plugin suite collected along the way, the practicalities, the “gotchas””, the pitfalls in human and development terms. I will also go into the details of down-to-earth examples, findings and tools we used to do it."