Bootstrapping a new Debian port of 18,000 source packages is always a massive job, and on average happens every year. This year it's arm64. This talk covers how such a port is done, and the work of the last two years (on multiarch, cross-tools, dependency-anaylsis tools and packaging infrastructure) to make this a repeatable and largely automated process, rather than an epic labour of hackery and bodging. It covers specific issues of the arm64 port, such as no hardware existing yet, and the current state of play.