diff --git a/.github/workflows/build-deploy-app.yml b/.github/workflows/build-deploy-app.yml
index cd9bdae4..a3621bbe 100644
--- a/.github/workflows/build-deploy-app.yml
+++ b/.github/workflows/build-deploy-app.yml
@@ -9,12 +9,17 @@ on:
       - "Makefile"
       - ".mvn"
       - ".gitignore"
+
+concurrency:
+  group: ${{github.workflow}}-${{github.ref}}
+  cancel-in-progress: true
+
 jobs:
   build-push:
     name: Build and push to registries
     # When releasing, the Maven release plugin will create two commits -
     # we only want this job to run once, so we exclude one of the commits.
-    if: ! contains(${{ github.event.head_commit.message }}, "prepare for next development iteration")
+    if: ${{ !contains(${{ github.event.head_commit.message }}, "prepare for next development iteration") }}
     runs-on: ubuntu-latest
     permissions:
       contents: read
@@ -206,4 +211,4 @@ jobs:
             ]
           }
       env:
-        SLACK_WEBHOOK_TYPE: INCOMING_WEBHOOK
\ No newline at end of file
+        SLACK_WEBHOOK_TYPE: INCOMING_WEBHOOK
diff --git a/flake.nix b/flake.nix
index 99c83f75..6e659bbb 100644
--- a/flake.nix
+++ b/flake.nix
@@ -10,16 +10,18 @@
     flake-parts.lib.mkFlake {inherit inputs;} {
       systems = ["x86_64-linux" "aarch64-linux" "aarch64-darwin" "x86_64-darwin"];
       perSystem = {
-        config,
-        self',
-        inputs',
         pkgs,
-        system,
         ...
       }: {
         devShells.default = pkgs.mkShell {
           name = "dapla-pseudo-service";
-          packages = with pkgs; [gnumake maven openjdk];
+          packages = with pkgs; [
+            gnumake
+            nixd
+            maven
+            openjdk
+            yaml-language-server
+          ];
         };
         formatter = pkgs.alejandra;
       };