Nix-based development environments at Shopify (reprise) (nixcon2025)

Over the past year at Shopify we've undergone a lot of changes internally. We moved from cloud development to local development, multirepo to monorepo, and Homebrew / Apt to Nix. Today, the majority of development is being done inside Nix-based environments. Some may recall that Shopify was using Nix back in 2019, so what happened? This talk will cover: * Why that effort stalled * How devenv reignited interest in Nix * How we approached incrementally migrating a huge collection of projects * Where we're at today, and lessons learned along the way * The many benefits Nix has brought * The challenges of supporting a large polygot org with developers working at every layer of the stack * Where we're headed about this event: https://talks.nixcon.org/nixcon-2025/talk/UPHTPD/