The COVID-19 pandemic has made abundantly clear how far our school systems are from being crisis-ready. The lockdowns seen across many parts of the world left schools and teachers scrambling to provide parents with whatever teaching materials they could find to enable some semblance of distance learning to take place. Despite heroic efforts, the immediate solutions found were far from optimal. This should not be surprising, since no curriculum or school system was ever designed with crisis-readiness in mind. In this article, we look back at the experience of school education during the pandemic, but mainly forward to what educational design can learn to make school curricula and systems more robust and crisis-ready. Taking the mathematics curriculum as our focus, we set out design strategies and tactics devised to ensure that all students are equitably engaged in productive struggle with important content and processes, feel that they have agency over their mathematics, and receive actionable formative feedback on their learning. Through a fully-worked out example, we illustrate the sorts of approaches that we envisage, and we conclude by discussing how we might transition towards such a curriculum.