diff --git a/app/models/clusters/cluster.rb b/app/models/clusters/cluster.rb
index 7a10b07ee9dea8b528cf4e1c6ad3ef11508e2fba..4262c03498d0f7255ecda30b256beb9b2a32d5a7 100644
--- a/app/models/clusters/cluster.rb
+++ b/app/models/clusters/cluster.rb
@@ -8,15 +8,17 @@ class Cluster < ApplicationRecord
 
     self.table_name = 'clusters'
 
+    PROJECT_ONLY_APPLICATIONS = {
+      Applications::Jupyter.application_name => Applications::Jupyter,
+      Applications::Knative.application_name => Applications::Knative,
+      Applications::Prometheus.application_name => Applications::Prometheus
+    }.freeze
     APPLICATIONS = {
       Applications::Helm.application_name => Applications::Helm,
       Applications::Ingress.application_name => Applications::Ingress,
       Applications::CertManager.application_name => Applications::CertManager,
-      Applications::Prometheus.application_name => Applications::Prometheus,
-      Applications::Runner.application_name => Applications::Runner,
-      Applications::Jupyter.application_name => Applications::Jupyter,
-      Applications::Knative.application_name => Applications::Knative
-    }.freeze
+      Applications::Runner.application_name => Applications::Runner
+    }.merge(PROJECT_ONLY_APPLICATIONS).freeze
     DEFAULT_ENVIRONMENT = '*'.freeze
     KUBE_INGRESS_BASE_DOMAIN = 'KUBE_INGRESS_BASE_DOMAIN'.freeze
 
diff --git a/app/services/clusters/applications/base_service.rb b/app/services/clusters/applications/base_service.rb
index cbd1cf03ae1407e4f67a61e148df91c0f684900e..14a454372874bf060cd0165653d0b18dc72d00d1 100644
--- a/app/services/clusters/applications/base_service.rb
+++ b/app/services/clusters/applications/base_service.rb
@@ -41,7 +41,7 @@ def worker_class(application)
         raise NotImplementedError
       end
 
-      def builders
+      def builder
         raise NotImplementedError
       end
 
@@ -50,11 +50,27 @@ def project_builders
       end
 
       def instantiate_application
-        builder.call(@cluster) || raise(InvalidApplicationError, "invalid application: #{application_name}")
+        raise_invalid_application_error if invalid_application?
+
+        builder || raise(InvalidApplicationError, "invalid application: #{application_name}")
       end
 
-      def builder
-        builders[application_name] || raise(InvalidApplicationError, "invalid application: #{application_name}")
+      def raise_invalid_application_error
+        raise(InvalidApplicationError, "invalid application: #{application_name}")
+      end
+
+      def invalid_application?
+        unknown_application? || (!cluster.project_type? && project_only_application?)
+      end
+
+      def unknown_application?
+        Clusters::Cluster::APPLICATIONS.keys.exclude?(application_name)
+      end
+
+      # These applications will need extra configuration to enable them to work
+      # with groups of projects
+      def project_only_application?
+        Clusters::Cluster::PROJECT_ONLY_APPLICATIONS.include?(application_name)
       end
 
       def application_name
diff --git a/app/services/clusters/applications/create_service.rb b/app/services/clusters/applications/create_service.rb
index c6f729aaa8aa6485a3129d5045f8dcaa912948cf..ae36da7b3ddeda222b78dd817c95e88af2550bf7 100644
--- a/app/services/clusters/applications/create_service.rb
+++ b/app/services/clusters/applications/create_service.rb
@@ -9,25 +9,9 @@ def worker_class(application)
         application.updateable? ? ClusterUpgradeAppWorker : ClusterInstallAppWorker
       end
 
-      def builders
-        {
-          "helm" => -> (cluster) { cluster.application_helm || cluster.build_application_helm },
-          "ingress" => -> (cluster) { cluster.application_ingress || cluster.build_application_ingress },
-          "cert_manager" => -> (cluster) { cluster.application_cert_manager || cluster.build_application_cert_manager },
-          "runner" => -> (cluster) { cluster.application_runner || cluster.build_application_runner }
-        }.tap do |hash|
-          hash.merge!(project_builders) if cluster.project_type?
-        end
-      end
-
-      # These applications will need extra configuration to enable them to work
-      # with groups of projects
-      def project_builders
-        {
-          "prometheus" => -> (cluster) { cluster.application_prometheus || cluster.build_application_prometheus },
-          "jupyter" => -> (cluster) { cluster.application_jupyter || cluster.build_application_jupyter },
-          "knative" => -> (cluster) { cluster.application_knative || cluster.build_application_knative }
-        }
+      def builder
+        cluster.method("application_#{application_name}").call ||
+          cluster.method("build_application_#{application_name}").call
       end
     end
   end
diff --git a/app/services/clusters/applications/update_service.rb b/app/services/clusters/applications/update_service.rb
index a9d4e60999263f6251f261d567dfd1fc7959090a..5071c31839c00c8782531449a345268b849d2643 100644
--- a/app/services/clusters/applications/update_service.rb
+++ b/app/services/clusters/applications/update_service.rb
@@ -9,25 +9,8 @@ def worker_class(application)
         ClusterPatchAppWorker
       end
 
-      def builders
-        {
-          "helm" => -> (cluster) { cluster.application_helm },
-          "ingress" => -> (cluster) { cluster.application_ingress },
-          "cert_manager" => -> (cluster) { cluster.application_cert_manager }
-        }.tap do |hash|
-          hash.merge!(project_builders) if cluster.project_type?
-        end
-      end
-
-      # These applications will need extra configuration to enable them to work
-      # with groups of projects
-      def project_builders
-        {
-          "prometheus" => -> (cluster) { cluster.application_prometheus },
-          "runner" => -> (cluster) { cluster.application_runner },
-          "jupyter" => -> (cluster) { cluster.application_jupyter },
-          "knative" => -> (cluster) { cluster.application_knative }
-        }
+      def builder
+        cluster.method("application_#{application_name}").call
       end
     end
   end