There's some conceptual overlap but I don't think the two tools are redundant. Using nix for development is sort of like having dedicated handcrafted developme

There's some conceptual overlap but I don't think the two tools are redundant. Using nix for development is sort of like having dedicated handcrafted development Docker containers for every single project... without having to ever use Docker or containers. You just get the sandboxing and safe reproducibility for free. It's kind of like having a build tool like cargo or stack, but for everything, all the time. You can fire up nix-shell for a project and just magically have the dependencies for that project available. There are tools like direnv and lorri that make this even easier and more powerful. Then, if you want to package up your project into a Docker image for deployment, you get that for free too. With all of that said, the magic is blunted a bit by some rough edges, missing packages here and there, etc. I wouldn't jump into nix expecting to have a completely polished and flawless experience like you can get with Docker, which is a much more mainstream project at this point. But I do think this will rapidly improve with nix, especially with large and well-known companies like Shopify using it.