If by "dependency resolution" you mean solving the SAT-equivalent constraint problem the article talks about, then yes, Nix does not do that. But, it does solv

If by "dependency resolution" you mean solving the SAT-equivalent constraint problem the article talks about, then yes, Nix does not do that. But, it does solve the simpler problem of installing a package along with the all of its transitive dependencies. Nix packages specify the exact version of each package it depends on, so you never have to recursively specify sub-dependencies. Installation is just a matter of walking an acyclic graph. It's not NP complete.