With free software, anyone can inspect the source code for malicious flaws. But Debian like most distribnutions provides binary packages to its users. The idea of “deterministic” or “reproducible” builds is to empower anyone to verify that no flaws have been introduced during the build process by reproducing byte-for-byte identical binary packages from a given source. This talk will explain the current status of the Debian Reproducible Builds project, how this is relevant for the complete free software eco system and how you can contribute. Holger 'h01ger' Levsen