At Release Engineering within Mozilla, we develop and support Firefox release pipelines that help Firefox developers test their patches and Release Management plan and execute Firefox releases. Release Engineering manage a number of services where each one aids in achieving these pipelines. e.g. kicking off and tracking a new release, analyzing the source code, and providing external dependencies for building and testing. Currently we use Nix to manage deployment and development of these services.. For this purpose, we wrote a small wrapper around Nix, to make interaction with Nix easier, and help with on-boarding. In this talk, I would like to share my experience of Nix adoption at Mozilla, especially within the Release Engineering / Management team. How we overcome some shortcoming of Nix-the-tool and what is still waiting for us to improve. What worked well and where Nix failed us. The main goal of this talk is to help others who are looking to introduce Nix at work, to know how to set expectations and what an such effort looks like. --- Bio: Rok is a Release Engineer at Mozilla, in Berlin. He is part of the Release Engineering team which helps ship Firefox and other Mozilla products. He is the author of pypi2nix tool, which tries to package python packages in Nix. In his free time … he hasn't had free time since his son was born.