diff --git a/README.md b/README.md
index 443ad6e..f83114c 100644
--- a/README.md
+++ b/README.md
@@ -35,8 +35,7 @@ Once your preferred template has been initialized, you can use the provided shel
 | [Elixir]                 | [`elixir`](./elixir/)     |
 | [Elm]                    | [`elm`](./elm/)           |
 | [Gleam]                  | [`gleam`](./gleam/)       |
-| [Go] 1.17                | [`go1_17`](./go1.17/)     |
-| [Go] 1.18                | [`go1_18`](./go1.18/)     |
+| [Go]                     | [`go`](./go/)             |
 | [Hashicorp] tools        | [`hashi`](./hashi/)       |
 | [Java]                   | [`java`](./java/)         |
 | [Kotlin]                 | [`kotlin`](./kotlin/)     |
@@ -96,15 +95,9 @@ The sections below list what each template includes. In all cases, you're free t
 
 - [Gleam] 0.22.1
 
-### [`go1.17`](./go1.17/)
+### [`go`](./go/)
 
-- [Go] 1.17
-- Standard Go tools ([goimports], [godoc], and others)
-- [golangci-lint]
-
-### [`go1.18`](./go1.18/)
-
-- [Go] 1.18
+- [Go] 1.19
 - Standard Go tools ([goimports], [godoc], and others)
 - [golangci-lint]
 
diff --git a/clojure/flake.nix b/clojure/flake.nix
index 4d79594..e440944 100644
--- a/clojure/flake.nix
+++ b/clojure/flake.nix
@@ -6,31 +6,38 @@
     nixpkgs.url = "github:NixOS/nixpkgs";
   };
 
-  outputs = { self, flake-utils, nixpkgs }:
+  outputs =
+    { self
+    , flake-utils
+    , nixpkgs
+    }:
+
     flake-utils.lib.eachDefaultSystem (system:
-      let
-        jdk = "jdk17";
-
-        config = {
-          packageOverrides = p: {
-            boot = p.boot.override { jdk = p.${jdk}; };
-            clojure = p.clojure.override { jdk = p.${jdk}; };
-            leiningen = p.leiningen.override { jdk = p.${jdk}; };
+    let
+      javaVersion = 17;
+      overlays = [
+        (self: super: rec {
+          jdk = super."jdk${toString javaVersion}";
+          boot = super.boot.override {
+            inherit jdk;
           };
-        };
-
-        pkgs = import nixpkgs { inherit config system; };
-        inherit (pkgs) boot clojure leiningen mkShell;
-      in
-      {
-        devShells = {
-          default = mkShell {
-            buildInputs = [ boot clojure leiningen ];
-
-            shellHook = ''
-              ${clojure}/bin/clj --version
-            '';
+          clojure = super.clojure.override {
+            inherit jdk;
           };
-        };
-      });
+          leiningen = super.leiningen.override {
+            inherit jdk;
+          };
+        })
+      ];
+      pkgs = import nixpkgs { inherit overlays system; };
+    in
+    {
+      devShell = pkgs.mkShell {
+        buildInputs = with pkgs; [ boot clojure leiningen ];
+
+        shellHook = ''
+          ${pkgs.clojure}/bin/clj --version
+        '';
+      };
+    });
 }
diff --git a/cue/flake.nix b/cue/flake.nix
index b185db4..ee28e0f 100644
--- a/cue/flake.nix
+++ b/cue/flake.nix
@@ -6,21 +6,23 @@
     nixpkgs.url = "github:NixOS/nixpkgs";
   };
 
-  outputs = { self, flake-utils, nixpkgs }:
-    flake-utils.lib.eachDefaultSystem (system:
-      let
-        pkgs = import nixpkgs { inherit system; };
-        inherit (pkgs) cue mkShell;
-      in
-      {
-        devShells = {
-          default = mkShell {
-            buildInputs = [ cue ];
+  outputs =
+    { self
+    , flake-utils
+    , nixpkgs
+    }:
 
-            shellHook = ''
-              ${cue}/bin/cue version
-            '';
-          };
-        };
-      });
+    flake-utils.lib.eachDefaultSystem (system:
+    let
+      pkgs = import nixpkgs { inherit system; };
+    in
+    {
+      devShell = pkgs.mkShell {
+        buildInputs = with pkgs; [ cue ];
+
+        shellHook = ''
+          ${pkgs.cue}/bin/cue version
+        '';
+      };
+    });
 }
diff --git a/dhall/flake.nix b/dhall/flake.nix
index 61a2187..c6d7813 100644
--- a/dhall/flake.nix
+++ b/dhall/flake.nix
@@ -6,47 +6,39 @@
     nixpkgs.url = "github:NixOS/nixpkgs";
   };
 
-  outputs = { self, flake-utils, nixpkgs }:
+  outputs =
+    { self
+    , flake-utils
+    , nixpkgs
+    }:
+
     flake-utils.lib.eachDefaultSystem (system:
-      let
-        pkgs = import nixpkgs { inherit system; };
-        dhall = pkgs.dhall;
+    let
+      pkgs = import nixpkgs { inherit system; };
 
-        inherit (pkgs) mkShell;
-        inherit (pkgs.lib) optionals;
-        inherit (pkgs.stdenv) isLinux;
+      # Helper function for building dhall-* tools
+      mkDhallTools = ls:
+        builtins.map (tool: pkgs.haskellPackages."dhall-${tool}") ls;
 
-        # Helper function for building dhall-* tools
-        mkDhallTools = ls:
-          builtins.map (tool: pkgs.haskellPackages."dhall-${tool}") ls;
+      dhallTools = mkDhallTools [
+        "bash"
+        "docs"
+        "json"
+        "lsp-server"
+        "nix"
+        "nixpkgs"
+        "openapi"
+        "toml"
+        "yaml"
+      ] ++ pkgs.lib.optionals (pkgs.stdenv.isLinux) (mkDhallTools [ "csv" "text" ]); # Linux only
+    in
+    {
+      devShell = pkgs.mkShell {
+        buildInputs = (with pkgs; [ dhall ]) ++ dhallTools;
 
-        # dhall-* tools available only on all platforms
-        dhallToolsCommon = mkDhallTools [
-          "bash"
-          "docs"
-          "json"
-          "lsp-server"
-          "nix"
-          "nixpkgs"
-          "openapi"
-          "toml"
-          "yaml"
-        ];
-
-        # dhall-* tools available only on Linux
-        dhallToolsLinux = optionals isLinux (mkDhallTools [ "csv" "text" ]);
-
-        dhallTools = dhallToolsCommon ++ dhallToolsLinux;
-      in
-      {
-        devShells = {
-          default = mkShell {
-            buildInputs = [ dhall ] ++ dhallTools;
-
-            shellHook = ''
-              echo "dhall `${dhall}/bin/dhall --version`"
-            '';
-          };
-        };
-      });
+        shellHook = ''
+          echo "dhall `${pkgs.dhall}/bin/dhall --version`"
+        '';
+      };
+    });
 }
diff --git a/elixir/flake.nix b/elixir/flake.nix
index a56d712..a6a2ece 100644
--- a/elixir/flake.nix
+++ b/elixir/flake.nix
@@ -6,32 +6,27 @@
     nixpkgs.url = "github:NixOS/nixpkgs";
   };
 
-  outputs = { self, flake-utils, nixpkgs }:
+  outputs =
+    { self
+    , flake-utils
+    , nixpkgs
+    }:
+
     flake-utils.lib.eachDefaultSystem (system:
-      let
-        pkgs = import nixpkgs { inherit system; };
+    let
+      pkgs = import nixpkgs { inherit system; };
+    in
+    {
+      devShell = pkgs.mkShell {
+        buildInputs = (with pkgs; [ elixir ]) ++
+          pkgs.lib.optionals (pkgs.stdenv.isLinux) (with pkgs; [ gigalixir inotify-tools libnotify ]) ++ # Linux only
+          pkgs.lib.optionals (pkgs.stdenv.isDarwin) (with pkgs; [ terminal-notifier ]) ++ # macOS only
+          (with pkgs.darwin.apple_sdk.frameworks; [ CoreFoundation CoreServices ]);
 
-        inherit (pkgs)
-          darwin gigalixir inotify-tools libnotify mkShell terminal-notifier;
-        inherit (pkgs.beam.packages.erlangR25) elixir elixir_ls;
-        inherit (pkgs.darwin.apple_sdk.frameworks) CoreFoundation CoreServices;
-        inherit (pkgs.lib) optionals;
-        inherit (pkgs.stdenv) isDarwin isLinux;
-
-        linuxDeps = optionals isLinux [ gigalixir inotify-tools libnotify ];
-        darwinDeps = optionals isDarwin [ terminal-notifier ]
-          ++ [ CoreFoundation CoreServices ];
-      in
-      {
-        devShells = {
-          default = mkShell {
-            buildInputs = [ elixir elixir_ls ] ++ linuxDeps ++ darwinDeps;
-
-            shellHook = ''
-              ${elixir}/bin/mix --version
-              ${elixir}/bin/iex --version
-            '';
-          };
-        };
-      });
+        shellHook = ''
+          ${pkgs.elixir}/bin/mix --version
+          ${pkgs.elixir}/bin/iex --version
+        '';
+      };
+    });
 }
diff --git a/elm/flake.nix b/elm/flake.nix
index cffc275..a2cabbe 100644
--- a/elm/flake.nix
+++ b/elm/flake.nix
@@ -6,23 +6,23 @@
     nixpkgs.url = "github:NixOS/nixpkgs";
   };
 
-  outputs = { self, flake-utils, nixpkgs }:
+  outputs =
+    { self
+    , flake-utils
+    , nixpkgs
+    }:
+
     flake-utils.lib.eachDefaultSystem (system:
-      let
-        pkgs = import nixpkgs { inherit system; };
-        inherit (pkgs) mkShell;
+    let
+      pkgs = import nixpkgs { inherit system; };
+    in
+    {
+      devShell = pkgs.mkShell {
+        buildInputs = (with pkgs.elmPackages; [ elm ]) ++ (with pkgs; [ elm2nix ]);
 
-        elm = pkgs.elmPackages.elm;
-      in
-      {
-        devShells = {
-          default = mkShell {
-            buildInputs = [ elm ] ++ (with pkgs; [ elm2nix ]);
-
-            shellHook = ''
-              echo "elm `${elm}/bin/elm --version`"
-            '';
-          };
-        };
-      });
+        shellHook = with pkgs.elmPackages; ''
+          echo "elm `${elm}/bin/elm --version`"
+        '';
+      };
+    });
 }
diff --git a/gleam/flake.nix b/gleam/flake.nix
index a8bd243..093ccdc 100644
--- a/gleam/flake.nix
+++ b/gleam/flake.nix
@@ -6,23 +6,23 @@
     nixpkgs.url = "github:NixOS/nixpkgs";
   };
 
-  outputs = { self, flake-utils, nixpkgs }:
+  outputs =
+    { self
+    , flake-utils
+    , nixpkgs
+    }:
+
     flake-utils.lib.eachDefaultSystem (system:
-      let
-        pkgs = import nixpkgs { inherit system; };
-        gleamPkg = pkgs.gleam;
+    let
+      pkgs = import nixpkgs { inherit system; };
+    in
+    {
+      devShell = pkgs.mkShell {
+        buildInputs = with pkgs; [ gleam ];
 
-        inherit (pkgs) mkShell;
-      in
-      {
-        devShells = {
-          default = mkShell {
-            buildInputs = [ gleamPkg ];
-
-            shellHook = ''
-              ${gleamPkg}/bin/gleam --version
-            '';
-          };
-        };
-      });
+        shellHook = ''
+          ${pkgs.gleam}/bin/gleam --version
+        '';
+      };
+    });
 }
diff --git a/go1.17/.envrc b/go/.envrc
similarity index 100%
rename from go1.17/.envrc
rename to go/.envrc
diff --git a/go1.17/flake.lock b/go/flake.lock
similarity index 100%
rename from go1.17/flake.lock
rename to go/flake.lock
diff --git a/go/flake.nix b/go/flake.nix
new file mode 100644
index 0000000..ac43480
--- /dev/null
+++ b/go/flake.nix
@@ -0,0 +1,39 @@
+{
+  description = "A Nix-flake-based Go 1.17 development environment";
+
+  inputs = {
+    flake-utils.url = "github:numtide/flake-utils";
+    nixpkgs.url = "github:NixOS/nixpkgs";
+  };
+
+  outputs =
+    { self
+    , flake-utils
+    , nixpkgs
+    }:
+
+    flake-utils.lib.eachDefaultSystem (system:
+    let
+      goVersion = 19;
+      overlays = [ (self: super: { go = super."go_1_${toString goVersion}"; }) ];
+      pkgs = import nixpkgs { inherit overlays system; };
+    in
+    {
+      devShell = pkgs.mkShellNoCC {
+        buildInputs = with pkgs; [
+          # go 1.17.1 (specified by overlay)
+          go
+
+          # goimports, godoc, etc.
+          gotools
+
+          # https://github.com/golangci/golangci-lint
+          golangci-lint
+        ];
+
+        shellHook = ''
+          ${pkgs.go}/bin/go version
+        '';
+      };
+    });
+}
diff --git a/go1.17/flake.nix b/go1.17/flake.nix
deleted file mode 100644
index 5ef8219..0000000
--- a/go1.17/flake.nix
+++ /dev/null
@@ -1,42 +0,0 @@
-{
-  description = "A Nix-flake-based Go 1.17 development environment";
-
-  inputs = {
-    flake-utils.url = "github:numtide/flake-utils";
-    nixpkgs.url = "github:NixOS/nixpkgs";
-  };
-
-  outputs = { self, flake-utils, nixpkgs }:
-    flake-utils.lib.eachDefaultSystem (system:
-      let
-        pkgs = import nixpkgs { inherit system; };
-        goPkg = pkgs.go_1_17;
-
-        inherit (pkgs) mkShellNoCC;
-      in
-      {
-        apps.default = {
-          type = "app";
-          program = "${goPkg}/bin/go";
-        };
-
-        devShells = {
-          default = mkShellNoCC {
-            buildInputs = with pkgs; [
-              # go 1.17.1
-              goPkg
-
-              # goimports, godoc, etc.
-              gotools
-
-              # https://github.com/golangci/golangci-lint
-              golangci-lint
-            ];
-
-            shellHook = ''
-              ${goPkg}/bin/go version
-            '';
-          };
-        };
-      });
-}
diff --git a/go1.18/.envrc b/go1.18/.envrc
deleted file mode 100644
index a5dbbcb..0000000
--- a/go1.18/.envrc
+++ /dev/null
@@ -1 +0,0 @@
-use flake .
diff --git a/go1.18/flake.lock b/go1.18/flake.lock
deleted file mode 100644
index 070c1f3..0000000
--- a/go1.18/flake.lock
+++ /dev/null
@@ -1,42 +0,0 @@
-{
-  "nodes": {
-    "flake-utils": {
-      "locked": {
-        "lastModified": 1659877975,
-        "narHash": "sha256-zllb8aq3YO3h8B/U0/J1WBgAL8EX5yWf5pMj3G0NAmc=",
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "rev": "c0e246b9b83f637f4681389ecabcb2681b4f3af0",
-        "type": "github"
-      },
-      "original": {
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "type": "github"
-      }
-    },
-    "nixpkgs": {
-      "locked": {
-        "lastModified": 1660984654,
-        "narHash": "sha256-fDcsh8rm2o8cj+WFL8Y2cAqnsej0UGJa+Sy8U2nFg0Q=",
-        "owner": "NixOS",
-        "repo": "nixpkgs",
-        "rev": "392c83491dcc21d17ab8ea1f809f8f7bd567a5a3",
-        "type": "github"
-      },
-      "original": {
-        "owner": "NixOS",
-        "repo": "nixpkgs",
-        "type": "github"
-      }
-    },
-    "root": {
-      "inputs": {
-        "flake-utils": "flake-utils",
-        "nixpkgs": "nixpkgs"
-      }
-    }
-  },
-  "root": "root",
-  "version": 7
-}
diff --git a/go1.18/flake.nix b/go1.18/flake.nix
deleted file mode 100644
index f4c40cd..0000000
--- a/go1.18/flake.nix
+++ /dev/null
@@ -1,42 +0,0 @@
-{
-  description = "A Nix-flake-based Go 1.18 development environment";
-
-  inputs = {
-    flake-utils.url = "github:numtide/flake-utils";
-    nixpkgs.url = "github:NixOS/nixpkgs";
-  };
-
-  outputs = { self, flake-utils, nixpkgs }:
-    flake-utils.lib.eachDefaultSystem (system:
-      let
-        pkgs = import nixpkgs { inherit system; };
-        goPkg = pkgs.go_1_18;
-
-        inherit (pkgs) mkShellNoCC;
-      in
-      {
-        apps.default = {
-          type = "app";
-          program = "${goPkg}/bin/go";
-        };
-
-        devShells = {
-          default = mkShellNoCC {
-            buildInputs = with pkgs; [
-              # go 1.18.3
-              goPkg
-
-              # goimports, godoc, etc.
-              gotools
-
-              # https://github.com/golangci/golangci-lint
-              golangci-lint
-            ];
-
-            shellHook = ''
-              ${goPkg}/bin/go version
-            '';
-          };
-        };
-      });
-}
diff --git a/hashi/flake.nix b/hashi/flake.nix
index 56ac35e..3fcb964 100644
--- a/hashi/flake.nix
+++ b/hashi/flake.nix
@@ -7,16 +7,19 @@
     nixpkgs.url = "github:NixOS/nixpkgs";
   };
 
-  outputs = { self, flake-utils, nixpkgs }:
+  outputs =
+    { self
+    , flake-utils
+    , nixpkgs
+    }:
+
     flake-utils.lib.eachDefaultSystem (system:
-      let
-        pkgs = import nixpkgs { inherit system; };
-
-        inherit (pkgs)
-          damon levant mkShell nomad nomad-autoscaler nomad-pack packer
-          terraform vault;
-
-        hashiTools = [
+    let
+      pkgs = import nixpkgs { inherit system; };
+    in
+    {
+      devShell = pkgs.mkShell {
+        buildInputs = with pkgs; [
           packer
           terraform
           nomad
@@ -25,22 +28,15 @@
           nomad-pack
           levant
           damon
+          terragrunt
         ];
 
-        relatedTools = with pkgs; [ terragrunt ];
-      in
-      {
-        devShells = {
-          default = mkShell {
-            buildInputs = hashiTools ++ relatedTools;
-
-            shellHook = ''
-              echo "packer `${packer}/bin/packer --version`"
-              ${terraform}/bin/terraform --version
-              ${nomad}/bin/nomad --version
-              ${vault}/bin/vault --version
-            '';
-          };
-        };
-      });
+        shellHook = with pkgs; ''
+          echo "packer `${packer}/bin/packer --version`"
+          ${terraform}/bin/terraform --version
+          ${nomad}/bin/nomad --version
+          ${vault}/bin/vault --version
+        '';
+      };
+    });
 }
diff --git a/haskell/flake.nix b/haskell/flake.nix
index 240a14b..505b5c6 100644
--- a/haskell/flake.nix
+++ b/haskell/flake.nix
@@ -6,22 +6,24 @@
     nixpkgs.url = "github:NixOS/nixpkgs";
   };
 
-  outputs = { self, flake-utils, nixpkgs }:
-    flake-utils.lib.eachDefaultSystem (system:
-      let
-        pkgs = import nixpkgs { inherit system; };
-        inherit (pkgs) cabal-install ghc mkShell;
-      in
-      {
-        devShells = {
-          default = mkShell {
-            buildInputs = [ cabal-install ghc ];
+  outputs =
+    { self
+    , flake-utils
+    , nixpkgs
+    }:
 
-            shellHook = ''
-              ${ghc}/bin/ghc --version
-              ${cabal-install}/bin/cabal --version
-            '';
-          };
-        };
-      });
+    flake-utils.lib.eachDefaultSystem (system:
+    let
+      pkgs = import nixpkgs { inherit system; };
+    in
+    {
+      devShell = pkgs.mkShell {
+        buildInputs = with pkgs; [ cabal-install ghc ];
+
+        shellHook = with pkgs; ''
+          ${ghc}/bin/ghc --version
+          ${cabal-install}/bin/cabal --version
+        '';
+      };
+    });
 }
diff --git a/java/flake.nix b/java/flake.nix
index f327551..bb4fba5 100644
--- a/java/flake.nix
+++ b/java/flake.nix
@@ -6,31 +6,37 @@
     nixpkgs.url = "github:NixOS/nixpkgs";
   };
 
-  outputs = { self, flake-utils, nixpkgs }:
+  outputs =
+    { self
+    , flake-utils
+    , nixpkgs
+    }:
+
     flake-utils.lib.eachDefaultSystem (system:
-      let
-        jdk = pkgs.jdk17;
+    let
+      javaVersion = 17;
 
-        config = {
-          packageOverrides = p: {
-            gradle = (p.gradle.override { java = jdk; });
+      overlays = [
+        (self: super: rec {
+          jdk = super."jdk${toString javaVersion}";
+          gradle = super.gradle.override {
+            java = jdk;
           };
-        };
-
-        pkgs = import nixpkgs { inherit config jdk system; };
-        java = jdk;
-        buildTools = with pkgs; [ ant gradle maven ];
-        inherit (pkgs) mkShell;
-      in
-      {
-        devShells = {
-          default = mkShell {
-            buildInputs = [ java ] ++ buildTools;
-
-            shellHook = ''
-              ${java}/bin/java -version
-            '';
+          maven = super.maven.override {
+            inherit jdk;
           };
-        };
-      });
+        })
+      ];
+
+      pkgs = import nixpkgs { inherit overlays system; };
+    in
+    {
+      devShell = pkgs.mkShell {
+        buildInputs = with pkgs; [ gradle jdk maven ];
+
+        shellHook = ''
+          ${pkgs.jdk}/bin/java -version
+        '';
+      };
+    });
 }
diff --git a/kotlin/flake.nix b/kotlin/flake.nix
index 99c3a73..488a2ee 100644
--- a/kotlin/flake.nix
+++ b/kotlin/flake.nix
@@ -6,35 +6,37 @@
     nixpkgs.url = "github:NixOS/nixpkgs";
   };
 
-  outputs = { self, flake-utils, nixpkgs }:
+  outputs =
+    { self
+    , flake-utils
+    , nixpkgs
+    }:
+
     flake-utils.lib.eachDefaultSystem (system:
-      let
-        jdk = pkgs.jdk17;
+    let
+      javaVersion = 17;
 
-        config = {
-          packageOverrides = p: {
-            gradle = (p.gradle.override { java = jdk; });
-
-            kotlin = (p.kotlin.override { jre = jdk; });
+      overlays = [
+        (self: super: rec {
+          jdk = pkgs."jdk${toString javaVersion}";
+          gradle = super.gradle.override {
+            java = jdk;
           };
-        };
-
-        pkgs = import nixpkgs { inherit config system; };
-        inherit (pkgs) mkShell;
-
-        kotlin = pkgs.kotlin;
-        buildTools = with pkgs; [ gradle ];
-        otherTools = with pkgs; [ gcc ncurses patchelf zlib ];
-      in
-      {
-        devShells = {
-          default = mkShell {
-            buildInputs = [ kotlin ] ++ buildTools ++ otherTools;
-
-            shellHook = ''
-              ${kotlin}/bin/kotlin -version
-            '';
+          kotlin = super.kotlin.override {
+            jre = jdk;
           };
-        };
-      });
+        })
+      ];
+
+      pkgs = import nixpkgs { inherit overlays system; };
+    in
+    {
+      devShell = pkgs.mkShell {
+        buildInputs = with pkgs; [ kotlin gradle gcc ncurses patchelf zlib ];
+
+        shellHook = ''
+          ${pkgs.kotlin}/bin/kotlin -version
+        '';
+      };
+    });
 }
diff --git a/nickel/flake.nix b/nickel/flake.nix
index 94a0904..d7157ff 100644
--- a/nickel/flake.nix
+++ b/nickel/flake.nix
@@ -6,21 +6,23 @@
     nixpkgs.url = "github:NixOS/nixpkgs";
   };
 
-  outputs = { self, flake-utils, nixpkgs }:
-    flake-utils.lib.eachDefaultSystem (system:
-      let
-        pkgs = import nixpkgs { inherit system; };
-        inherit (pkgs) mkShell nickel;
-      in
-      {
-        devShells = {
-          default = mkShell {
-            buildInputs = [ nickel ];
+  outputs =
+    { self
+    , flake-utils
+    , nixpkgs
+    }:
 
-            shellHook = ''
-              ${nickel}/bin/nickel --version
-            '';
-          };
-        };
-      });
+    flake-utils.lib.eachDefaultSystem (system:
+    let
+      pkgs = import nixpkgs { inherit system; };
+    in
+    {
+      devShell = pkgs.mkShell {
+        buildInputs = with pkgs; [ nickel ];
+
+        shellHook = ''
+          ${pkgs.nickel}/bin/nickel --version
+        '';
+      };
+    });
 }
diff --git a/nim/flake.nix b/nim/flake.nix
index e270319..a67f6f0 100644
--- a/nim/flake.nix
+++ b/nim/flake.nix
@@ -6,21 +6,23 @@
     nixpkgs.url = "github:NixOS/nixpkgs";
   };
 
-  outputs = { self, flake-utils, nixpkgs }:
-    flake-utils.lib.eachDefaultSystem (system:
-      let
-        pkgs = import nixpkgs { inherit system; };
-        inherit (pkgs) mkShell nim;
-      in
-      {
-        devShells = {
-          default = mkShell {
-            buildInputs = [ nim ];
+  outputs =
+    { self
+    , flake-utils
+    , nixpkgs
+    }:
 
-            shellHook = ''
-              ${nim}/bin/nim --version
-            '';
-          };
-        };
-      });
+    flake-utils.lib.eachDefaultSystem (system:
+    let
+      pkgs = import nixpkgs { inherit system; };
+    in
+    {
+      devShell = pkgs.mkShell {
+        buildInputs = with pkgs; [ nim ];
+
+        shellHook = ''
+          ${pkgs.nim}/bin/nim --version
+        '';
+      };
+    });
 }
diff --git a/nix/flake.nix b/nix/flake.nix
index 23a1b95..6c931e9 100644
--- a/nix/flake.nix
+++ b/nix/flake.nix
@@ -6,26 +6,27 @@
     nixpkgs.url = "github:NixOS/nixpkgs";
   };
 
-  outputs = { self, flake-utils, nixpkgs }:
+  outputs =
+    { self
+    , flake-utils
+    , nixpkgs
+    }:
+
     flake-utils.lib.eachDefaultSystem (system:
-      let
-        pkgs = import nixpkgs { inherit system; };
-
-        dhallNix = pkgs.haskellPackages.dhall-nix;
-
-        nixRelatedTools = with pkgs; [
+    let
+      pkgs = import nixpkgs { inherit system; };
+    in
+    {
+      devShell = {
+        buildInputs = with pkgs; [
           cachix
-          dhallNix
           lorri
           niv
           nixfmt
           statix
           vulnix
+          haskellPackages.dhall-nix
         ];
-
-        inherit (pkgs) mkShell;
-      in
-      {
-        devShells = { default = mkShell { buildInputs = nixRelatedTools; }; };
-      });
+      };
+    });
 }
diff --git a/node/flake.nix b/node/flake.nix
index 94810ec..7fba182 100644
--- a/node/flake.nix
+++ b/node/flake.nix
@@ -6,26 +6,30 @@
     nixpkgs.url = "github:NixOS/nixpkgs";
   };
 
-  outputs = { self, flake-utils, nixpkgs }:
+  outputs =
+    { self
+    , flake-utils
+    , nixpkgs
+    }:
+
     flake-utils.lib.eachDefaultSystem (system:
-      let
-        nodeOverlay = self: super: rec {
+    let
+      overlays = [
+        (self: super: rec {
           nodejs = super.nodejs-18_x;
           pnpm = super.nodePackages.pnpm;
           yarn = (super.yarn.override { inherit nodejs; });
-        };
-        overlays = [ nodeOverlay ];
-        pkgs = import nixpkgs { inherit overlays system; };
-      in
-      {
-        devShells = {
-          default = pkgs.mkShell {
-            buildInputs = with pkgs; [ node2nix nodejs pnpm yarn ];
+        })
+      ];
+      pkgs = import nixpkgs { inherit overlays system; };
+    in
+    {
+      devShell = pkgs.mkShell {
+        buildInputs = with pkgs; [ node2nix nodejs pnpm yarn ];
 
-            shellHook = ''
-              echo "node `${pkgs.nodejs}/bin/node --version`"
-            '';
-          };
-        };
-      });
+        shellHook = ''
+          echo "node `${pkgs.nodejs}/bin/node --version`"
+        '';
+      };
+    });
 }
diff --git a/ocaml/flake.nix b/ocaml/flake.nix
index e1cf7b5..800e6d9 100644
--- a/ocaml/flake.nix
+++ b/ocaml/flake.nix
@@ -6,24 +6,24 @@
     nixpkgs.url = "github:NixOS/nixpkgs";
   };
 
-  outputs = { self, flake-utils, nixpkgs }:
-    flake-utils.lib.eachDefaultSystem (system:
-      let
-        pkgs = import nixpkgs { inherit system; };
-        inherit (pkgs) mkShell;
-        ocaml = pkgs.ocamlPackages.ocaml;
-        ocamlTools = with pkgs.ocamlPackages;
-          [ dune_3 odoc ] ++ (with pkgs; [ ocamlformat ]);
-      in
-      {
-        devShells = {
-          default = mkShell {
-            buildInputs = [ ocaml ] ++ ocamlTools;
+  outputs =
+    { self
+    , flake-utils
+    , nixpkgs
+    }:
 
-            shellHook = ''
-              ${ocaml}/bin/ocaml --version
-            '';
-          };
-        };
-      });
+    flake-utils.lib.eachDefaultSystem (system:
+    let
+      pkgs = import nixpkgs { inherit system; };
+    in
+    {
+      devShell = pkgs.mkShell {
+        buildInputs = with pkgs; [ ocaml ocamlformat ] ++
+          (with pkgs.ocamlPackages; [ dune_3 odoc ]);
+
+        shellHook = ''
+          ${pkgs.ocaml}/bin/ocaml --version
+        '';
+      };
+    });
 }
diff --git a/opa/flake.nix b/opa/flake.nix
index a82f479..4d6599b 100644
--- a/opa/flake.nix
+++ b/opa/flake.nix
@@ -6,23 +6,23 @@
     nixpkgs.url = "github:NixOS/nixpkgs";
   };
 
-  outputs = { self, flake-utils, nixpkgs }:
+  outputs =
+    { self
+    , flake-utils
+    , nixpkgs
+    }:
+
     flake-utils.lib.eachDefaultSystem (system:
-      let
-        pkgs = import nixpkgs { inherit system; };
-        inherit (pkgs) conftest mkShell open-policy-agent;
+    let
+      pkgs = import nixpkgs { inherit system; };
+    in
+    {
+      devShell = pkgs.mkShell {
+        buildInputs = with pkgs; [ open-policy-agent conftest ];
 
-        opaTools = [ conftest open-policy-agent ];
-      in
-      {
-        devShells = {
-          default = mkShell {
-            buildInputs = opaTools;
-
-            shellHook = ''
-              ${open-policy-agent}/bin/opa version
-            '';
-          };
-        };
-      });
+        shellHook = ''
+          ${pkgs.open-policy-agent}/bin/opa version
+        '';
+      };
+    });
 }
diff --git a/protobuf/flake.nix b/protobuf/flake.nix
index a3176ae..b4bb3bf 100644
--- a/protobuf/flake.nix
+++ b/protobuf/flake.nix
@@ -6,22 +6,23 @@
     nixpkgs.url = "github:NixOS/nixpkgs";
   };
 
-  outputs = { self, flake-utils, nixpkgs }:
+  outputs =
+    { self
+    , flake-utils
+    , nixpkgs
+    }:
     flake-utils.lib.eachDefaultSystem (system:
-      let
-        pkgs = import nixpkgs { inherit system; };
-        inherit (pkgs) buf mkShell protobuf;
-      in
-      {
-        devShells = {
-          default = mkShell {
-            buildInputs = [ buf protobuf ];
+    let
+      pkgs = import nixpkgs { inherit system; };
+    in
+    {
+      devShell = pkgs.mkShell {
+        buildInputs = with pkgs; [ buf protobuf ];
 
-            shellHook = ''
-              echo "buf `${buf}/bin/buf --version`"
-              ${protobuf}/bin/protoc --version
-            '';
-          };
-        };
-      });
+        shellHook = with pkgs; ''
+          echo "buf `${buf}/bin/buf --version`"
+          ${protobuf}/bin/protoc --version
+        '';
+      };
+    });
 }
diff --git a/python/flake.nix b/python/flake.nix
index f153a9d..8cd5c1a 100644
--- a/python/flake.nix
+++ b/python/flake.nix
@@ -7,29 +7,31 @@
     nixpkgs.url = "github:NixOS/nixpkgs";
   };
 
-  outputs = { self, flake-utils, mach-nix, nixpkgs }:
+  outputs =
+    { self
+    , flake-utils
+    , mach-nix
+    , nixpkgs
+    }:
     flake-utils.lib.eachDefaultSystem (system:
-      let
-        pkgs = import nixpkgs { inherit system; };
-        inherit (pkgs) mkShell;
+    let
+      overlays = [
+        (self: super: {
+          machNix = mach-nix.defaultPackage.${system};
+          python = super.python311;
+        })
+      ];
 
-        python = pkgs.python311;
+      pkgs = import nixpkgs { inherit overlays system; };
+    in
+    {
+      devShell = pkgs.mkShell {
+        buildInputs = with pkgs; [ python machNix virtualenv ] ++
+          (with pkgs.python311Packages; [ pip ]);
 
-        machNix = mach-nix.defaultPackage.${system};
-
-        pythonTools = with pkgs;
-          [ virtualenv ] ++ (with pkgs.python311Packages; [ pip ]);
-        nixTools = [ machNix ];
-      in
-      {
-        devShells = {
-          default = mkShell {
-            buildInputs = [ python ] ++ pythonTools ++ nixTools;
-
-            shellHook = ''
-              ${python}/bin/python --version
-            '';
-          };
-        };
-      });
+        shellHook = ''
+          ${pkgs.python}/bin/python --version
+        '';
+      };
+    });
 }
diff --git a/ruby/flake.nix b/ruby/flake.nix
index 2b9db26..91d97aa 100644
--- a/ruby/flake.nix
+++ b/ruby/flake.nix
@@ -6,23 +6,27 @@
     nixpkgs.url = "github:NixOS/nixpkgs";
   };
 
-  outputs = { self, flake-utils, nixpkgs }:
+  outputs =
+    { self
+    , flake-utils
+    , nixpkgs
+    }:
     flake-utils.lib.eachDefaultSystem (system:
-      let
-        pkgs = import nixpkgs { inherit system; };
-        inherit (pkgs) mkShell;
+    let
+      overlays = [
+        (self: super: {
+          ruby = super.ruby_3_1;
+        })
+      ];
+      pkgs = import nixpkgs { inherit overlays system; };
+    in
+    {
+      devShell = pkgs.mkShell {
+        buildInputs = with pkgs; [ ruby ];
 
-        ruby = pkgs.ruby_3_1;
-      in
-      {
-        devShells = {
-          default = mkShell {
-            buildInputs = [ ruby ];
-
-            shellHook = ''
-              ${ruby}/bin/ruby --version
-            '';
-          };
-        };
-      });
+        shellHook = ''
+          ${pkgs.ruby}/bin/ruby --version
+        '';
+      };
+    });
 }
diff --git a/rust/flake.nix b/rust/flake.nix
index 1b56f52..6650643 100644
--- a/rust/flake.nix
+++ b/rust/flake.nix
@@ -7,41 +7,48 @@
     rust-overlay.url = "github:oxalica/rust-overlay";
   };
 
-  outputs = { self, flake-utils, nixpkgs, rust-overlay }:
+  outputs =
+    { self
+    , flake-utils
+    , nixpkgs
+    , rust-overlay
+    }:
+
     flake-utils.lib.eachDefaultSystem (system:
-      let
-        overlays = [ (import rust-overlay) ];
+    let
+      overlays = [
+        (import rust-overlay)
+        (self: super: {
+          rustToolchain =
+            let
+              rust = super.rust-bin;
+            in
+            if builtins.pathExists ./rust-toolchain.toml then
+              rust.fromRustupToolchainFile ./rust-toolchain.toml
+            else if builtins.pathExists ./rust-toolchain then
+              rust.fromRustupToolchainFile ./rust-toolchain
+            else
+              rust.stable.latest.default;
+        })
+      ];
 
-        pkgs = import nixpkgs { inherit system overlays; };
+      pkgs = import nixpkgs { inherit system overlays; };
+    in
+    {
+      devShell = pkgs.mkShell {
+        nativeBuildInputs = with pkgs; [
+          rustToolchain
+          openssl
+          pkg-config
+          cargo-audit
+          cargo-deny
+          cargo-cross
+          rust-analyzer
+        ] ++ pkgs.lib.optionals (pkgs.stdenv.isLinux) (with pkgs; [ cargo-watch ]); # Currently broken on macOS
 
-        inherit (pkgs) mkShell rust-bin;
-        inherit (pkgs.lib) optionals;
-        inherit (pkgs.stdenv) isLinux;
-
-        rust =
-          if builtins.pathExists ./rust-toolchain.toml then
-            rust-bin.fromRustupToolchainFile ./rust-toolchain.toml
-          else if builtins.pathExists ./rust-toolchain then
-            rust-bin.fromRustupToolchainFile ./rust-toolchain
-          else
-            rust-bin.stable.latest.default;
-
-        deps = with pkgs; [ openssl pkgconfig ];
-        rustTools = with pkgs;
-          [ cargo-audit cargo-deny cargo-cross rust-analyzer ]
-          ++ optionals isLinux (with pkgs; [ cargo-watch ]);
-      in
-      {
-        packages.default = rust;
-
-        devShells = {
-          default = mkShell {
-            nativeBuildInputs = [ rust ] ++ deps ++ rustTools;
-
-            shellHook = ''
-              ${rust}/bin/cargo --version
-            '';
-          };
-        };
-      });
+        shellHook = ''
+          ${pkgs.rustToolchain}/bin/cargo --version
+        '';
+      };
+    });
 }
diff --git a/scala/flake.nix b/scala/flake.nix
index 90d7d21..76b8129 100644
--- a/scala/flake.nix
+++ b/scala/flake.nix
@@ -6,35 +6,37 @@
     nixpkgs.url = "github:NixOS/nixpkgs";
   };
 
-  outputs = { self, flake-utils, nixpkgs }:
+  outputs =
+    { self
+    , flake-utils
+    , nixpkgs
+    }:
     flake-utils.lib.eachDefaultSystem (system:
-      let
-        jdk = "jdk17";
 
-        config = {
-          packageOverrides = p: {
-            sbt = p.sbt.override { jre = p.${jdk}; };
-            scala_3 = p.scala_3.override { jre = p.${jdk}; };
+    let
+      javaVersion = 17;
+
+      overlays = [
+        (self: super: rec {
+          jdk = super."jdk${toString javaVersion}";
+          sbt = super.sbt.override {
+            jre = jdk;
           };
-        };
-
-        pkgs = import nixpkgs { inherit config jdk system; };
-
-        inherit (pkgs) mkShell;
-
-        scala = pkgs.scala_3;
-
-        buildTools = with pkgs; [ sbt ];
-      in
-      {
-        devShells = {
-          default = mkShell {
-            buildInputs = [ scala ] ++ buildTools;
-
-            shellHook = ''
-              ${scala}/bin/scala -version
-            '';
+          scala = super.scala_3.override {
+            jre = jdk;
           };
-        };
-      });
+        })
+      ];
+
+      pkgs = import nixpkgs { inherit overlays system; };
+    in
+    {
+      devShell = pkgs.mkShell {
+        buildInputs = with pkgs; [ scala sbt coursier ];
+
+        shellHook = ''
+          ${pkgs.scala}/bin/scala -version
+        '';
+      };
+    });
 }
diff --git a/zig/flake.nix b/zig/flake.nix
index 842940c..7ab0ba9 100644
--- a/zig/flake.nix
+++ b/zig/flake.nix
@@ -6,23 +6,23 @@
     nixpkgs.url = "github:NixOS/nixpkgs";
   };
 
-  outputs = { self, flake-utils, nixpkgs }:
+  outputs =
+    { self
+    , flake-utils
+    , nixpkgs
+    }:
+
     flake-utils.lib.eachDefaultSystem (system:
-      let
-        pkgs = import nixpkgs { inherit system; };
-        zigPkg = pkgs.zig;
+    let
+      pkgs = import nixpkgs { inherit system; };
+    in
+    {
+      devShell = pkgs.mkShell {
+        buildInputs = with pkgs; [ zig ];
 
-        inherit (pkgs) mkShell;
-      in
-      {
-        devShells = {
-          default = mkShell {
-            buildInputs = [ zigPkg ];
-
-            shellHook = ''
-              echo "zig `${zigPkg}/bin/zig version`"
-            '';
-          };
-        };
-      });
+        shellHook = ''
+          echo "zig `${pkgs.zig}/bin/zig version`"
+        '';
+      };
+    });
 }