like this one

• [Nix-dev] Introducing Nixpkgs Overlays
• Video - Initial announcement of overlays by Nicolas B. Pierron (nbp)
• Overlays implementation by Nicolas B. Pierron (nbp)
• https://nixos.wiki/wiki/Overlays
• Gabriel439/haskell-nix issue #58
• NixOS: The DOs and DON’Ts of nixpkgs overlays
• Nix overlays and override pattern Stackoverflow thread

Should packageOverrides be deprecated in favor of Overlays?

• Nixpkgs issue - Deprecate packageOverrides? #43266
• Nixpkgs pull request - [WIP] Deprecate packageOverrides #43560