diff --git a/ee/lib/remote_development/devfile_operations/restrictions_enforcer.rb b/ee/lib/remote_development/devfile_operations/restrictions_enforcer.rb
index 377735942395430bb0af3234fcbb89d90ffde511..143a1f7d78d2d65b83055fd0e19dd43194eb68cb 100644
--- a/ee/lib/remote_development/devfile_operations/restrictions_enforcer.rb
+++ b/ee/lib/remote_development/devfile_operations/restrictions_enforcer.rb
@@ -6,6 +6,8 @@ class RestrictionsEnforcer
       include RemoteDevelopmentConstants
       include Messages
 
+      MAX_DEVFILE_SIZE_BYTES = 3.megabytes
+
       # Since this is called after flattening the devfile, we can safely assume that it has valid syntax
       # as per devfile standard. If you are validating something that is not available across all devfile versions,
       # add additional guard clauses.
@@ -22,12 +24,19 @@ class RestrictionsEnforcer
       SUPPORTED_COMMAND_TYPES = %i[exec apply].freeze
 
       # Currently, we only support `preStart` events
-      SUPPORTED_EVENTS = %i[preStart].freeze
+      SUPPORTED_EVENTS = %i[preStart postStart].freeze
+
+      # Currently, we only support the following options for exec commands
+      SUPPORTED_EXEC_COMMAND_OPTIONS = %i[commandLine component label hotReloadCapable].freeze
+
+      # Currently, we only support the default value `false` for the `hotReloadCapable` option
+      SUPPORTED_HOT_RELOAD_VALUE = false
 
       # @param [Hash] context
       # @return [Gitlab::Fp::Result]
       def self.enforce(context)
         Gitlab::Fp::Result.ok(context)
+                          .and_then(method(:validate_devfile_size))
                           .and_then(method(:validate_schema_version))
                           .and_then(method(:validate_parent))
                           .and_then(method(:validate_projects))
@@ -40,6 +49,8 @@ def self.enforce(context)
                           .and_then(method(:validate_variables))
       end
 
+      private
+
       # @param [Hash] context
       # @return [Hash] the `processed_devfile` out of the `context` if it exists, otherwise the `devfile`
       def self.devfile_to_validate(context)
@@ -48,6 +59,29 @@ def self.devfile_to_validate(context)
         context[:processed_devfile] || context[:devfile]
       end
 
+      # @param [Hash] context
+      # @return [Gitlab::Fp::Result]
+      def self.validate_devfile_size(context)
+        devfile = devfile_to_validate(context)
+
+        # Calculate the size of the devfile by converting it to JSON
+        devfile_json = devfile.to_json
+        devfile_size_bytes = devfile_json.bytesize
+
+        if devfile_size_bytes > MAX_DEVFILE_SIZE_BYTES
+          return err(
+            format(
+              _("Devfile size (%{current_size}) exceeds the maximum allowed size of %{max_size}"),
+              current_size: ActiveSupport::NumberHelper.number_to_human_size(devfile_size_bytes),
+              max_size: ActiveSupport::NumberHelper.number_to_human_size(MAX_DEVFILE_SIZE_BYTES)
+            ),
+            context
+          )
+        end
+
+        Gitlab::Fp::Result.ok(context)
+      end
+
       # @param [Hash] context
       # @return [Gitlab::Fp::Result]
       def self.validate_schema_version(context)
@@ -131,6 +165,7 @@ def self.validate_components(context)
         end
 
         if injected_main_components.length > 1
+          # noinspection RailsParamDefResolve -- this pluck isn't from ActiveRecord, it's from ActiveSupport
           return err(
             format(
               _("Multiple components '%{name}' have '%{attribute}' attribute"),
@@ -242,48 +277,82 @@ def self.validate_endpoints(context)
       def self.validate_commands(context)
         devfile = devfile_to_validate(context)
 
-        # Ensure no command name starts with restricted_prefix
         devfile.fetch(:commands, []).each do |command|
           command_id = command.fetch(:id)
-          if command_id.downcase.start_with?(RESTRICTED_PREFIX)
+
+          # Check command_id for restricted prefix
+          error_result = validate_restricted_prefix(command_id, 'command_id', context)
+          return error_result if error_result
+
+          supported_command_type = SUPPORTED_COMMAND_TYPES.find { |type| command[type].present? }
+
+          unless supported_command_type
             return err(
               format(
-                _("Command id '%{command}' must not start with '%{prefix}'"),
+                _("Command '%{command}' must have one of the supported command types: %{supported_types}"),
                 command: command_id,
-                prefix: RESTRICTED_PREFIX
+                supported_types: SUPPORTED_COMMAND_TYPES.join(", ")
               ),
               context
             )
           end
 
           # Ensure no command is referring to a component with restricted_prefix
-          SUPPORTED_COMMAND_TYPES.each do |supported_command_type|
-            command_type = command[supported_command_type]
-            next unless command_type
+          command_type = command[supported_command_type]
+
+          # Check if component is present (required for both exec and apply)
+          unless command_type[:component].present?
+            return err(
+              format(
+                _("'%{type}' command '%{command}' must specify a 'component'"),
+                type: supported_command_type,
+                command: command_id
+              ),
+              context
+            )
+          end
 
-            component_name = command_type.fetch(:component)
+          # Check component name for restricted prefix
+          component_name = command_type.fetch(:component)
 
-            if component_name.downcase.start_with?(RESTRICTED_PREFIX)
-              return err(
-                format(
-                  _("Component name '%{component}' for command id '%{command}' must not start with '%{prefix}'"),
-                  component: component_name,
-                  command: command_id,
-                  prefix: RESTRICTED_PREFIX
-                ),
-                context
-              )
-            end
+          error_result = validate_restricted_prefix(component_name, 'component_name', context,
+            { command: command_id })
+          return error_result if error_result
 
-            command_label = command_type.fetch(:label, "")
-            next unless command_label.downcase.start_with?(RESTRICTED_PREFIX)
+          # Check label for restricted prefix
+          command_label = command_type.fetch(:label, "")
 
+          error_result = validate_restricted_prefix(command_label, 'label', context,
+            { command: command_id })
+          return error_result if command_label.present? && error_result
+
+          # Type-specicific validations for `exec` commands
+          # Since we only support the exec command type for user defined poststart events
+          # We don't need to have validation for other command types
+          next unless supported_command_type == :exec
+
+          exec_command = command_type
+
+          # Validate that only the supported options are used
+          unsupported_options = exec_command.keys - SUPPORTED_EXEC_COMMAND_OPTIONS
+          if unsupported_options.any?
             return err(
               format(
-                _("Label '%{command_label}' for command id '%{command}' must not start with '%{prefix}'"),
-                command_label: command_label,
+                _("Unsupported options '%{options}' for exec command '%{command}'. " \
+                  "Only '%{supported_options}' are supported."),
+                options: unsupported_options.join(", "),
                 command: command_id,
-                prefix: RESTRICTED_PREFIX
+                supported_options: SUPPORTED_EXEC_COMMAND_OPTIONS.join(", ")
+              ),
+              context
+            )
+          end
+
+          if exec_command.key?(:hotReloadCapable) && exec_command[:hotReloadCapable] != SUPPORTED_HOT_RELOAD_VALUE
+            return err(
+              format(
+                _("Property 'hotReloadCapable' for exec command '%{command}' must be false when specified"),
+                command: command_id
               ),
               context
             )
@@ -293,10 +362,44 @@ def self.validate_commands(context)
         Gitlab::Fp::Result.ok(context)
       end
 
+      # @param [String] value
+      # @param [String] type
+      # @param [Hash] context
+      # @param [Hash] additional_params
+      # @return [Gitlab::Fp::Result.err]
+      def self.validate_restricted_prefix(value, type, context, additional_params = {})
+        return unless value.downcase.start_with?(RESTRICTED_PREFIX)
+
+        error_messages = {
+          'command_id' => _("Command id '%{command}' must not start with '%{prefix}'"),
+          'component_name' => _(
+            "Component name '%{component}' for command id '%{command}' must not start with '%{prefix}'"
+          ),
+          'label' => _("Label '%{command_label}' for command id '%{command}' must not start with '%{prefix}'")
+        }
+
+        message_template = error_messages[type]
+        return unless message_template
+
+        params = { prefix: RESTRICTED_PREFIX }.merge(additional_params)
+
+        case type
+        when 'command_id'
+          params[:command] = value
+        when 'component_name'
+          params[:component] = value
+        when 'label'
+          params[:command_label] = value
+        end
+
+        err(format(message_template, params), context)
+      end
+
       # @param [Hash] context
       # @return [Gitlab::Fp::Result]
       def self.validate_events(context)
         devfile = devfile_to_validate(context)
+        commands = devfile.fetch(:commands, [])
 
         devfile.fetch(:events, {}).each do |event_type, event_type_events|
           # Ensure no event type other than "preStart" are allowed
@@ -308,18 +411,35 @@ def self.validate_events(context)
           end
 
           # Ensure no event starts with restricted_prefix
-          event_type_events.each do |event|
-            next unless event.downcase.start_with?(RESTRICTED_PREFIX)
+          event_type_events.each do |command_name|
+            if command_name.downcase.start_with?(RESTRICTED_PREFIX)
+              return err(
+                format(
+                  _("Event '%{event}' of type '%{event_type}' must not start with '%{prefix}'"),
+                  event: command_name,
+                  event_type: event_type,
+                  prefix: RESTRICTED_PREFIX
+                ),
+                context
+              )
+            end
 
-            return err(
-              format(
-                _("Event '%{event}' of type '%{event_type}' must not start with '%{prefix}'"),
-                event: event,
-                event_type: event_type,
-                prefix: RESTRICTED_PREFIX
-              ),
-              context
-            )
+            next unless event_type == :postStart
+
+            # ===== postStart specific validations =====
+
+            # Check if the referenced command is an exec command
+            referenced_command = commands.find { |cmd| cmd[:id] == command_name }
+            unless referenced_command[:exec].present?
+              return err(
+                format(
+                  _("PostStart event references command '%{command}' which is not an exec command. Only exec " \
+                    "commands are supported in postStart events"),
+                  command: command_name
+                ),
+                context
+              )
+            end
           end
         end
 
@@ -358,9 +478,9 @@ def self.validate_variables(context)
       def self.err(details, context)
         Gitlab::Fp::Result.err(DevfileRestrictionsFailed.new({ details: details, context: context }))
       end
-      private_class_method :devfile_to_validate, :validate_schema_version, :validate_parent,
+      private_class_method :devfile_to_validate, :validate_devfile_size, :validate_schema_version, :validate_parent,
         :validate_projects, :validate_components, :validate_containers,
-        :validate_endpoints, :validate_commands, :validate_events,
+        :validate_endpoints, :validate_commands, :validate_restricted_prefix, :validate_events,
         :validate_variables, :err, :validate_root_attributes
     end
   end
diff --git a/ee/lib/remote_development/workspace_operations/create/internal_poststart_commands_inserter.rb b/ee/lib/remote_development/workspace_operations/create/internal_poststart_commands_inserter.rb
index 02290ae04cc8e89dc8e4b28490714e43e04e1515..5016c9924ca65aff535a71aed1909ec066d25f29 100644
--- a/ee/lib/remote_development/workspace_operations/create/internal_poststart_commands_inserter.rb
+++ b/ee/lib/remote_development/workspace_operations/create/internal_poststart_commands_inserter.rb
@@ -66,7 +66,6 @@ def self.insert(context)
               label: INTERNAL_BLOCKING_COMMAND_LABEL
             }
           }
-          poststart_events << clone_project_command_id
 
           # Add the start_sshd event
           start_sshd_command_id = "gl-start-sshd-command"
@@ -78,7 +77,6 @@ def self.insert(context)
               label: INTERNAL_BLOCKING_COMMAND_LABEL
             }
           }
-          poststart_events << start_sshd_command_id
 
           # Add the start_vscode event
           start_vscode_command_id = "gl-init-tools-command"
@@ -90,7 +88,6 @@ def self.insert(context)
               label: INTERNAL_BLOCKING_COMMAND_LABEL
             }
           }
-          poststart_events << start_vscode_command_id
 
           # Add the sleep_until_container_is_running event
           sleep_until_container_is_running_command_id = "gl-sleep-until-container-is-running-command"
@@ -108,7 +105,14 @@ def self.insert(context)
               label: INTERNAL_COMMAND_LABEL
             }
           }
-          poststart_events << sleep_until_container_is_running_command_id
+
+          # Prepend internal commands so they are executed before any user-defined poststart events.
+          poststart_events.prepend(
+            clone_project_command_id,
+            start_sshd_command_id,
+            start_vscode_command_id,
+            sleep_until_container_is_running_command_id
+          )
 
           context
         end
diff --git a/ee/lib/remote_development/workspace_operations/reconcile/output/scripts_configmap_appender.rb b/ee/lib/remote_development/workspace_operations/reconcile/output/scripts_configmap_appender.rb
index 95c0f49594e5d83941e940b53d11e39199a13733..e5f042689a5ffa0018f2e2d5de6e2a23d729a534 100644
--- a/ee/lib/remote_development/workspace_operations/reconcile/output/scripts_configmap_appender.rb
+++ b/ee/lib/remote_development/workspace_operations/reconcile/output/scripts_configmap_appender.rb
@@ -99,7 +99,6 @@ def self.add_run_poststart_commands_script_to_configmap_data(
 
             # Segregate internal commands and user provided commands.
             # Before any non-blocking post start command is executed, we wait for the workspace to be marked ready.
-            # TODO: User provided commands should be added to the non-blocking poststart script with https://gitlab.com/gitlab-org/gitlab/-/issues/505988
             internal_blocking_poststart_command_ids, non_blocking_poststart_command_ids =
               poststart_command_ids.partition do |id|
                 command = devfile_commands.find { |cmd| cmd[:id] == id }
diff --git a/ee/spec/features/remote_development/workspaces_spec.rb b/ee/spec/features/remote_development/workspaces_spec.rb
index fc9fd01def4cdb7ed2c821bca0a47eff130d66b5..84ae7ff39568c1d8ff4f4a68cac7cad5e04d53c2 100644
--- a/ee/spec/features/remote_development/workspaces_spec.rb
+++ b/ee/spec/features/remote_development/workspaces_spec.rb
@@ -35,6 +35,19 @@
   let(:variable_value) { "value 1" }
   let(:workspaces_group_settings_path) { "/groups/#{group.name}/-/settings/workspaces" }
 
+  let(:user_defined_commands) do
+    [
+      {
+        id: "user-defined-command",
+        exec: {
+          component: "tooling-container",
+          commandLine: "echo 'user-defined postStart command'",
+          hotReloadCapable: false
+        }
+      }
+    ]
+  end
+
   # @param [String] state
   # @return [void]
   def expect_workspace_state_indicator(state)
@@ -168,7 +181,8 @@ def do_reconcile_post(params:, agent_token:)
           dns_zone: workspaces_agent_config.dns_zone,
           namespace_path: group.path,
           project_name: project.path,
-          image_pull_secrets: image_pull_secrets
+          image_pull_secrets: image_pull_secrets,
+          user_defined_commands: user_defined_commands
         )
 
       # SIMULATE RECONCILE RESPONSE TO AGENTK SENDING NEW WORKSPACE
diff --git a/ee/spec/fixtures/remote_development/example.devfile.yaml.erb b/ee/spec/fixtures/remote_development/example.devfile.yaml.erb
index cae2fcd1d74330ef65db39dac570337b3be93ff3..b23ec15cc93a0f151d0c8722c721f4fd64aa1fb8 100644
--- a/ee/spec/fixtures/remote_development/example.devfile.yaml.erb
+++ b/ee/spec/fixtures/remote_development/example.devfile.yaml.erb
@@ -12,4 +12,13 @@ components:
       env:
         - name: MYSQL_ROOT_PASSWORD
           value: "my-secret-pw"
-
+commands:
+  - id: user-defined-command
+    exec:
+      component: tooling-container
+      commandLine: echo 'user-defined postStart command'
+      hotReloadCapable: false
+events:
+  preStart: []
+  postStart:
+    - user-defined-command
diff --git a/ee/spec/fixtures/remote_development/example.flattened-devfile.yaml.erb b/ee/spec/fixtures/remote_development/example.flattened-devfile.yaml.erb
index ddb034751444d00b70161fdbd4347cc7bd7fb8c3..a1ab14be9569e1575d7958f5abe39f85e65dfd36 100644
--- a/ee/spec/fixtures/remote_development/example.flattened-devfile.yaml.erb
+++ b/ee/spec/fixtures/remote_development/example.flattened-devfile.yaml.erb
@@ -17,9 +17,14 @@ components:
       env:
         - name: MYSQL_ROOT_PASSWORD
           value: "my-secret-pw"
-commands: []
-events: {
-  preStart: [],
-  postStart: []
-}
+commands:
+  - id: user-defined-command
+    exec:
+      component: tooling-container
+      commandLine: echo 'user-defined postStart command'
+      hotReloadCapable: false
+events:
+  postStart:
+    - user-defined-command
+  preStart: []
 variables: {}
diff --git a/ee/spec/fixtures/remote_development/example.internal-poststart-commands-inserted-devfile.yaml.erb b/ee/spec/fixtures/remote_development/example.internal-poststart-commands-inserted-devfile.yaml.erb
index 1c73ef9b7214c348911aec49f3520372ec6299ca..93b06e24fff62a04ee6e5c7c2124a6bbfc7638df 100644
--- a/ee/spec/fixtures/remote_development/example.internal-poststart-commands-inserted-devfile.yaml.erb
+++ b/ee/spec/fixtures/remote_development/example.internal-poststart-commands-inserted-devfile.yaml.erb
@@ -55,6 +55,11 @@ components:
       cpuLimit: 500m
       cpuRequest: 100m
 commands:
+  - id: user-defined-command
+    exec:
+      component: tooling-container
+      commandLine: echo 'user-defined postStart command'
+      hotReloadCapable: false
   - id: gl-tools-injector-command
     apply:
       component: gl-tools-injector
@@ -99,4 +104,5 @@ events:
     - gl-start-sshd-command
     - gl-init-tools-command
     - gl-sleep-until-container-is-running-command
+    - user-defined-command
 variables: {}
diff --git a/ee/spec/fixtures/remote_development/example.invalid-command-missing-component-devfile.yaml.erb b/ee/spec/fixtures/remote_development/example.invalid-command-missing-component-devfile.yaml.erb
new file mode 100644
index 0000000000000000000000000000000000000000..2d2d69306788bdda8a18d165ec5abd982fa14f42
--- /dev/null
+++ b/ee/spec/fixtures/remote_development/example.invalid-command-missing-component-devfile.yaml.erb
@@ -0,0 +1,12 @@
+---
+schemaVersion: 2.2.0
+components:
+  - name: example
+    attributes:
+      gl/inject-editor: true
+    container:
+      image: quay.io/mloriedo/universal-developer-image:ubi8-dw-demo
+commands:
+  - id: missing-component-command
+    exec:
+      commandLine: echo "Hello, World!"
diff --git a/ee/spec/fixtures/remote_development/example.invalid-restricted-prefix-command-exec-component-name-devfile.yaml.erb b/ee/spec/fixtures/remote_development/example.invalid-restricted-prefix-command-exec-component-name-devfile.yaml.erb
index eb67d6ca6a35c3e634fd82bcdcd502cf83114500..73128597de04722355126980133da18c64c11e83 100644
--- a/ee/spec/fixtures/remote_development/example.invalid-restricted-prefix-command-exec-component-name-devfile.yaml.erb
+++ b/ee/spec/fixtures/remote_development/example.invalid-restricted-prefix-command-exec-component-name-devfile.yaml.erb
@@ -11,6 +11,5 @@ commands:
     exec:
       component: gl-example
       commandLine: mvn clean
-      workingDir: /projects/spring-petclinic
 events: {}
 variables: {}
diff --git a/ee/spec/fixtures/remote_development/example.invalid-restricted-prefix-command-exec-label-devfile.yaml.erb b/ee/spec/fixtures/remote_development/example.invalid-restricted-prefix-command-exec-label-devfile.yaml.erb
index 599d5ed62eb43c27b2fb7ad663f73818fdd20e76..b4ed85beacf4294fdf4afc7cf3d6a24b2df9e415 100644
--- a/ee/spec/fixtures/remote_development/example.invalid-restricted-prefix-command-exec-label-devfile.yaml.erb
+++ b/ee/spec/fixtures/remote_development/example.invalid-restricted-prefix-command-exec-label-devfile.yaml.erb
@@ -11,7 +11,6 @@ commands:
     exec:
       component: example
       commandLine: mvn clean
-      workingDir: /projects/spring-petclinic
       label: gl-example
 events: {}
 variables: {}
diff --git a/ee/spec/fixtures/remote_development/example.invalid-restricted-prefix-command-name-devfile.yaml.erb b/ee/spec/fixtures/remote_development/example.invalid-restricted-prefix-command-name-devfile.yaml.erb
index 6db207f3f7bfe5b00a4157db940e855031611300..63acc386c83e3aa1b82c16cb0a91c997b3f90540 100644
--- a/ee/spec/fixtures/remote_development/example.invalid-restricted-prefix-command-name-devfile.yaml.erb
+++ b/ee/spec/fixtures/remote_development/example.invalid-restricted-prefix-command-name-devfile.yaml.erb
@@ -11,6 +11,5 @@ commands:
     exec:
       component: example
       commandLine: mvn clean
-      workingDir: /projects/spring-petclinic
 events: {}
 variables: {}
diff --git a/ee/spec/fixtures/remote_development/example.invalid-restricted-prefix-event-type-prestop-name-devfile.yaml.erb b/ee/spec/fixtures/remote_development/example.invalid-restricted-prefix-event-type-prestop-name-devfile.yaml.erb
index beb62f964e72a9dd2d985d39f6562c65b41aff2c..1ca19380ddf32614a91c544c8b9040a71ea2cf32 100644
--- a/ee/spec/fixtures/remote_development/example.invalid-restricted-prefix-event-type-prestop-name-devfile.yaml.erb
+++ b/ee/spec/fixtures/remote_development/example.invalid-restricted-prefix-event-type-prestop-name-devfile.yaml.erb
@@ -11,7 +11,6 @@ commands:
     exec:
       component: example
       commandLine: mvn clean
-      workingDir: /projects/spring-petclinic
 events:
   preStop:
     - example
diff --git a/ee/spec/fixtures/remote_development/example.invalid-unsupported-command-exec-hot-reload-capable-option-devfile.yaml.erb b/ee/spec/fixtures/remote_development/example.invalid-unsupported-command-exec-hot-reload-capable-option-devfile.yaml.erb
new file mode 100644
index 0000000000000000000000000000000000000000..697529b3185693aca2041436bbbcc3489bc50fd8
--- /dev/null
+++ b/ee/spec/fixtures/remote_development/example.invalid-unsupported-command-exec-hot-reload-capable-option-devfile.yaml.erb
@@ -0,0 +1,14 @@
+---
+schemaVersion: 2.2.0
+components:
+  - name: example
+    attributes:
+      gl/inject-editor: true
+    container:
+      image: quay.io/mloriedo/universal-developer-image:ubi8-dw-demo
+commands:
+  - id: unsupported-hot-reload-option
+    exec:
+      component: example
+      commandLine: echo "Hello, World!"
+      hotReloadCapable: true
diff --git a/ee/spec/fixtures/remote_development/example.invalid-unsupported-command-exec-options-devfile.yaml.erb b/ee/spec/fixtures/remote_development/example.invalid-unsupported-command-exec-options-devfile.yaml.erb
new file mode 100644
index 0000000000000000000000000000000000000000..2b981466a5b799e96167f13419c4f644b3c5db20
--- /dev/null
+++ b/ee/spec/fixtures/remote_development/example.invalid-unsupported-command-exec-options-devfile.yaml.erb
@@ -0,0 +1,14 @@
+---
+schemaVersion: 2.2.0
+components:
+  - name: example
+    attributes:
+      gl/inject-editor: true
+    container:
+      image: quay.io/mloriedo/universal-developer-image:ubi8-dw-demo
+commands:
+  - id: unsupported-options
+    exec:
+      component: example
+      commandLine: echo "Hello, World!"
+      unsupportedOption: true
diff --git a/ee/spec/fixtures/remote_development/example.invalid-unsupported-command-type-devfile.yaml.erb b/ee/spec/fixtures/remote_development/example.invalid-unsupported-command-type-devfile.yaml.erb
new file mode 100644
index 0000000000000000000000000000000000000000..9fff21edcfc5462530466f1cc14c03c1f487b2b9
--- /dev/null
+++ b/ee/spec/fixtures/remote_development/example.invalid-unsupported-command-type-devfile.yaml.erb
@@ -0,0 +1,12 @@
+---
+schemaVersion: 2.2.0
+components:
+  - name: example
+    attributes:
+      gl/inject-editor: true
+    container:
+      image: quay.io/mloriedo/universal-developer-image:ubi8-dw-demo
+commands:
+  - id: composite-command
+    composite:
+      commands: []
diff --git a/ee/spec/fixtures/remote_development/example.invalid-unsupported-event-type-poststart-devfile.yaml.erb b/ee/spec/fixtures/remote_development/example.invalid-unsupported-command-type-poststart-event-devfile.yaml.erb
similarity index 65%
rename from ee/spec/fixtures/remote_development/example.invalid-unsupported-event-type-poststart-devfile.yaml.erb
rename to ee/spec/fixtures/remote_development/example.invalid-unsupported-command-type-poststart-event-devfile.yaml.erb
index 49133608fe5134ffa7375f2a88f9146864526054..4960e26035d0673edc2e933bcdde2107f43f2fc7 100644
--- a/ee/spec/fixtures/remote_development/example.invalid-unsupported-event-type-poststart-devfile.yaml.erb
+++ b/ee/spec/fixtures/remote_development/example.invalid-unsupported-command-type-poststart-event-devfile.yaml.erb
@@ -7,12 +7,9 @@ components:
     container:
       image: quay.io/mloriedo/universal-developer-image:ubi8-dw-demo
 commands:
-  - id: example
-    exec:
+  - id: apply-command
+    apply:
       component: example
-      commandLine: mvn clean
-      workingDir: /projects/spring-petclinic
 events:
   postStart:
-    - example
-variables: {}
+    - apply-command
diff --git a/ee/spec/fixtures/remote_development/example.invalid-unsupported-event-type-prestop-devfile.yaml.erb b/ee/spec/fixtures/remote_development/example.invalid-unsupported-event-type-prestop-devfile.yaml.erb
index 63039bf768db94ffb200d16b4464baa63a643b1f..bcfe5f1cb47ef639598a594be4c2f8bc5ce78749 100644
--- a/ee/spec/fixtures/remote_development/example.invalid-unsupported-event-type-prestop-devfile.yaml.erb
+++ b/ee/spec/fixtures/remote_development/example.invalid-unsupported-event-type-prestop-devfile.yaml.erb
@@ -11,7 +11,6 @@ commands:
     exec:
       component: example
       commandLine: mvn clean
-      workingDir: /projects/spring-petclinic
 events:
   preStop:
     - example
diff --git a/ee/spec/fixtures/remote_development/example.main-container-updated-devfile.yaml.erb b/ee/spec/fixtures/remote_development/example.main-container-updated-devfile.yaml.erb
index 2740b5f509fa6d2b8c5185f7b4f94a276ed198f5..65f71c915b09080adcaf3f648ebb2e3847303009 100644
--- a/ee/spec/fixtures/remote_development/example.main-container-updated-devfile.yaml.erb
+++ b/ee/spec/fixtures/remote_development/example.main-container-updated-devfile.yaml.erb
@@ -55,11 +55,17 @@ components:
       cpuLimit: 500m
       cpuRequest: 100m
 commands:
+  - id: user-defined-command
+    exec:
+      component: tooling-container
+      commandLine: echo 'user-defined postStart command'
+      hotReloadCapable: false
   - id: gl-tools-injector-command
     apply:
       component: gl-tools-injector
 events:
   preStart:
     - gl-tools-injector-command
-  postStart: []
+  postStart:
+    - user-defined-command
 variables: {}
diff --git a/ee/spec/fixtures/remote_development/example.main-container-updated-marketplace-disabled-devfile.yaml.erb b/ee/spec/fixtures/remote_development/example.main-container-updated-marketplace-disabled-devfile.yaml.erb
index 2740b5f509fa6d2b8c5185f7b4f94a276ed198f5..65f71c915b09080adcaf3f648ebb2e3847303009 100644
--- a/ee/spec/fixtures/remote_development/example.main-container-updated-marketplace-disabled-devfile.yaml.erb
+++ b/ee/spec/fixtures/remote_development/example.main-container-updated-marketplace-disabled-devfile.yaml.erb
@@ -55,11 +55,17 @@ components:
       cpuLimit: 500m
       cpuRequest: 100m
 commands:
+  - id: user-defined-command
+    exec:
+      component: tooling-container
+      commandLine: echo 'user-defined postStart command'
+      hotReloadCapable: false
   - id: gl-tools-injector-command
     apply:
       component: gl-tools-injector
 events:
   preStart:
     - gl-tools-injector-command
-  postStart: []
+  postStart:
+    - user-defined-command
 variables: {}
diff --git a/ee/spec/fixtures/remote_development/example.multi-entry-devfile.yaml.erb b/ee/spec/fixtures/remote_development/example.multi-entry-devfile.yaml.erb
index 8a37e943a53aee50f4436074931419e32de85f91..cdbdb84a7f38f1245d52d9bd93c1f3ed9cbe2acf 100644
--- a/ee/spec/fixtures/remote_development/example.multi-entry-devfile.yaml.erb
+++ b/ee/spec/fixtures/remote_development/example.multi-entry-devfile.yaml.erb
@@ -20,15 +20,10 @@ components:
           protocol: https
           exposure: none
 commands:
-  - id: example-valid-non-apply-or-exec-command
-    composite:
-      commands:
-        - example-valid-command
-        - example-valid-second-command
-      parallel: false
   - id: example-valid-command
-    apply:
+    exec:
       component: example-valid-component
+      commandLine: echo "valid command"
   - id: example-valid-second-command
     apply:
       component: example-valid-second-component
diff --git a/ee/spec/fixtures/remote_development/example.processed-devfile.yaml.erb b/ee/spec/fixtures/remote_development/example.processed-devfile.yaml.erb
index 9e596cd810835de4c8c4df72ceac39f73719027f..6e824aaa12d67e5c0944a4781166972042ee5a6d 100644
--- a/ee/spec/fixtures/remote_development/example.processed-devfile.yaml.erb
+++ b/ee/spec/fixtures/remote_development/example.processed-devfile.yaml.erb
@@ -67,6 +67,11 @@ components:
     volume:
       size: 50Gi
 commands:
+  - id: user-defined-command
+    exec:
+      component: tooling-container
+      commandLine: echo 'user-defined postStart command'
+      hotReloadCapable: false
   - id: gl-tools-injector-command
     apply:
       component: gl-tools-injector
@@ -111,4 +116,5 @@ events:
     - gl-start-sshd-command
     - gl-init-tools-command
     - gl-sleep-until-container-is-running-command
+    - user-defined-command
 variables: {}
diff --git a/ee/spec/fixtures/remote_development/example.tools-injector-inserted-devfile.yaml.erb b/ee/spec/fixtures/remote_development/example.tools-injector-inserted-devfile.yaml.erb
index 52180a5d81234940ff5729ea7dd9afc7c8092787..57754eda21c8fce0f2f964fc70735fef630589da 100644
--- a/ee/spec/fixtures/remote_development/example.tools-injector-inserted-devfile.yaml.erb
+++ b/ee/spec/fixtures/remote_development/example.tools-injector-inserted-devfile.yaml.erb
@@ -30,8 +30,14 @@ components:
 events:
   preStart:
     - gl-tools-injector-command
-  postStart: []
+  postStart:
+    - user-defined-command
 commands:
+  - id: user-defined-command
+    exec:
+      component: tooling-container
+      commandLine: echo 'user-defined postStart command'
+      hotReloadCapable: false
   - id: gl-tools-injector-command
     apply:
       component: gl-tools-injector
diff --git a/ee/spec/lib/remote_development/devfile_operations/flattener_spec.rb b/ee/spec/lib/remote_development/devfile_operations/flattener_spec.rb
index bcbdd8a6bb5ef5aee82f000626e4a14dd40da887..abba522ef442d2c658619d506fe855d4774ab0c2 100644
--- a/ee/spec/lib/remote_development/devfile_operations/flattener_spec.rb
+++ b/ee/spec/lib/remote_development/devfile_operations/flattener_spec.rb
@@ -25,6 +25,16 @@
     )
   end
 
+  it "removes unsupported exec command options" do
+    result_value = result.unwrap
+    exec_command = result_value[:processed_devfile][:commands].first[:exec]
+
+    supported_options = RemoteDevelopment::DevfileOperations::RestrictionsEnforcer::SUPPORTED_EXEC_COMMAND_OPTIONS
+
+    # Should keep only supported options
+    expect(exec_command.keys).to all(be_in(supported_options))
+  end
+
   context "when devfile has no elements" do
     let(:devfile_yaml) { read_devfile_yaml('example.invalid-no-elements-devfile.yaml.erb') }
     let(:expected_processed_devfile) do
diff --git a/ee/spec/lib/remote_development/devfile_operations/restrictions_enforcer_spec.rb b/ee/spec/lib/remote_development/devfile_operations/restrictions_enforcer_spec.rb
index 20bc9be47c8849a76345c1272152a1433424471b..6e665c33bad781d1d93c43a344500964322535ed 100644
--- a/ee/spec/lib/remote_development/devfile_operations/restrictions_enforcer_spec.rb
+++ b/ee/spec/lib/remote_development/devfile_operations/restrictions_enforcer_spec.rb
@@ -68,6 +68,7 @@
         "example.invalid-attributes-tools-injector-absent-devfile.yaml.erb" | "No component has '#{main_component_indicator_attribute}' attribute"
         "example.invalid-attributes-tools-injector-multiple-devfile.yaml.erb" | "Multiple components '[\"tooling-container\", \"tooling-container-2\"]' have '#{main_component_indicator_attribute}' attribute"
         "example.invalid-component-missing-name.yaml.erb" | "Components must have a 'name'"
+        "example.invalid-command-missing-component-devfile.yaml.erb" | "'exec' command 'missing-component-command' must specify a 'component'"
         "example.invalid-components-attributes-container-overrides-devfile.yaml.erb" | "Attribute 'container-overrides' is not yet supported"
         "example.invalid-components-attributes-pod-overrides-devfile.yaml.erb" | "Attribute 'pod-overrides' is not yet supported"
         "example.invalid-components-entry-empty-devfile.yaml.erb" | "No components present in devfile"
@@ -86,11 +87,14 @@
         "example.invalid-restricted-prefix-command-exec-label-devfile.yaml.erb" | "Label 'gl-example' for command id 'example' must not start with 'gl-'"
         "example.invalid-restricted-prefix-variable-name-with-underscore-devfile.yaml.erb" | "Variable name 'gl_example' must not start with 'gl_'"
         "example.invalid-root-attributes-pod-overrides-devfile.yaml.erb" | "Attribute 'pod-overrides' is not yet supported"
+        "example.invalid-unsupported-command-exec-hot-reload-capable-option-devfile.yaml.erb" | "Property 'hotReloadCapable' for exec command 'unsupported-hot-reload-option' must be false when specified"
+        "example.invalid-unsupported-command-exec-options-devfile.yaml.erb" | "Unsupported options 'unsupportedOption' for exec command 'unsupported-options'. Only 'commandLine, component, label, hotReloadCapable' are supported."
+        "example.invalid-unsupported-command-type-devfile.yaml.erb" | "Command 'composite-command' must have one of the supported command types: exec, apply"
+        "example.invalid-unsupported-command-type-poststart-event-devfile.yaml.erb" | "PostStart event references command 'apply-command' which is not an exec command. Only exec commands are supported in postStart events"
         "example.invalid-unsupported-component-container-dedicated-pod-devfile.yaml.erb" | "Property 'dedicatedPod' of component 'example' is not yet supported"
         "example.invalid-unsupported-component-type-image-devfile.yaml.erb" | "Component type 'image' is not yet supported"
         "example.invalid-unsupported-component-type-kubernetes-devfile.yaml.erb" | "Component type 'kubernetes' is not yet supported"
         "example.invalid-unsupported-component-type-openshift-devfile.yaml.erb" | "Component type 'openshift' is not yet supported"
-        "example.invalid-unsupported-event-type-poststart-devfile.yaml.erb" | "Event type 'postStart' is not yet supported"
         "example.invalid-unsupported-event-type-poststop-devfile.yaml.erb" | "Event type 'postStop' is not yet supported"
         "example.invalid-unsupported-event-type-prestop-devfile.yaml.erb" | "Event type 'preStop' is not yet supported"
         "example.invalid-unsupported-parent-inheritance-devfile.yaml.erb" | "Inheriting from 'parent' is not yet supported"
@@ -135,5 +139,26 @@
         it_behaves_like "an err result"
       end
     end
+
+    context "for devfile size validation" do
+      let(:input_devfile_name) { "example.devfile.yaml.erb" }
+
+      context "when devfile exceeds maximum size" do
+        before do
+          json_string = input_devfile.to_json
+          allow(input_devfile).to receive(:to_json).and_return(json_string)
+          allow(json_string).to receive(:bytesize).and_return(3.megabytes + 1)
+        end
+
+        it "returns an err Result with size exceeded message" do
+          is_expected.to be_err_result do |message|
+            expect(message).to be_a(RemoteDevelopment::Messages::DevfileRestrictionsFailed)
+            message.content => { details: String => error_details, context: Hash => actual_context }
+            expect(error_details).to match(/Devfile size .* exceeds the maximum allowed size/)
+            expect(actual_context).to eq(context)
+          end
+        end
+      end
+    end
   end
 end
diff --git a/ee/spec/lib/remote_development/workspace_operations/reconcile/main_integration_spec.rb b/ee/spec/lib/remote_development/workspace_operations/reconcile/main_integration_spec.rb
index 8094515d369a313712e3e88d162193223021637a..0402ccb54cf07fbd6471f55b883e0479096a07c8 100644
--- a/ee/spec/lib/remote_development/workspace_operations/reconcile/main_integration_spec.rb
+++ b/ee/spec/lib/remote_development/workspace_operations/reconcile/main_integration_spec.rb
@@ -71,6 +71,19 @@
 
   let(:logger) { instance_double(::Logger) }
 
+  let(:user_defined_commands) do
+    [
+      {
+        id: "user-defined-command",
+        exec: {
+          component: "tooling-container",
+          commandLine: "echo 'user-defined postStart command'",
+          hotReloadCapable: false
+        }
+      }
+    ]
+  end
+
   let(:expected_config_to_apply_yaml_stream) do
     create_config_to_apply_yaml_stream(
       workspace: workspace,
@@ -84,7 +97,8 @@
       egress_ip_rules: egress_ip_rules,
       max_resources_per_workspace: max_resources_per_workspace,
       default_resources_per_workspace_container: default_resources_per_workspace_container,
-      image_pull_secrets: image_pull_secrets
+      image_pull_secrets: image_pull_secrets,
+      user_defined_commands: user_defined_commands
     )
   end
 
@@ -261,6 +275,33 @@
       it_behaves_like 'unprovisioned workspace expectations'
       it_behaves_like 'versioned workspaces_agent_configs behavior'
     end
+
+    context 'when workspace has user-defined postStart commands' do
+      it 'includes user-defined commands in the scripts configmap' do
+        workspace_rails_infos = response.fetch(:payload).fetch(:workspace_rails_infos)
+        actual_workspace_rails_info = workspace_rails_infos.detect { |info| info.fetch(:name) == workspace.name }
+        actual_config_to_apply =
+          yaml_safe_load_stream_symbolized(actual_workspace_rails_info.fetch(:config_to_apply))
+
+        scripts_configmap = actual_config_to_apply.find do |resource|
+          resource[:kind] == "ConfigMap" && resource[:metadata][:name].end_with?("-scripts-configmap")
+        end
+
+        expect(scripts_configmap).to be_present
+
+        expect(scripts_configmap[:data].keys).to include(user_defined_commands.first[:id].to_sym)
+
+        expect(scripts_configmap[:data][user_defined_commands.first[:id].to_sym]).to eq(
+          user_defined_commands.first[:exec][:commandLine]
+        )
+
+        # Verify the poststart script includes the user-defined command
+        poststart_script = scripts_configmap[:data][
+          reconcile_constants_module::RUN_NON_BLOCKING_POSTSTART_COMMANDS_SCRIPT_NAME.to_sym
+        ]
+        expect(poststart_script).to include("Running /workspace-scripts/user-defined-command")
+      end
+    end
   end
 
   context 'when update_type is partial' do
diff --git a/ee/spec/lib/remote_development/workspace_operations/reconcile/output/desired_config_generator_spec.rb b/ee/spec/lib/remote_development/workspace_operations/reconcile/output/desired_config_generator_spec.rb
index 3b8b83f9568fd3bc41e86f9c25a99017b9dc4579..026c50e63826ba4dd9ee8a20a938d5e65a0c4aa7 100644
--- a/ee/spec/lib/remote_development/workspace_operations/reconcile/output/desired_config_generator_spec.rb
+++ b/ee/spec/lib/remote_development/workspace_operations/reconcile/output/desired_config_generator_spec.rb
@@ -79,6 +79,19 @@
       )
     end
 
+    let(:user_defined_commands) do
+      [
+        {
+          id: "user-defined-command",
+          exec: {
+            component: "tooling-container",
+            commandLine: "echo 'user-defined postStart command'",
+            hotReloadCapable: false
+          }
+        }
+      ]
+    end
+
     let(:expected_config) do
       create_config_to_apply(
         workspace: workspace,
@@ -98,7 +111,8 @@
         agent_labels: workspace.workspaces_agent_config.labels.deep_symbolize_keys,
         agent_annotations: workspace.workspaces_agent_config.annotations.deep_symbolize_keys,
         image_pull_secrets: image_pull_secrets.map(&:deep_symbolize_keys),
-        shared_namespace: shared_namespace
+        shared_namespace: shared_namespace,
+        user_defined_commands: user_defined_commands
       )
     end
 
@@ -293,6 +307,8 @@
         read_devfile_yaml("example.legacy-poststart-in-container-command-processed-devfile.yaml.erb")
       end
 
+      let(:user_defined_commands) { [] }
+
       it 'returns expected config without script resources' do
         expect(workspace_resources).to eq(expected_config)
       end
diff --git a/ee/spec/lib/remote_development/workspace_operations/reconcile/output/scripts_configmap_appender_spec.rb b/ee/spec/lib/remote_development/workspace_operations/reconcile/output/scripts_configmap_appender_spec.rb
index 23c9eca6be6a3cc184f48c107118150f9de1bde0..e6d1c62b1b098458f331adee4cd480f8387560b8 100644
--- a/ee/spec/lib/remote_development/workspace_operations/reconcile/output/scripts_configmap_appender_spec.rb
+++ b/ee/spec/lib/remote_development/workspace_operations/reconcile/output/scripts_configmap_appender_spec.rb
@@ -55,10 +55,11 @@
       reconcile_constants_module::RUN_INTERNAL_BLOCKING_POSTSTART_COMMANDS_SCRIPT_NAME.to_sym =>
         internal_blocking_poststart_commands_script,
       reconcile_constants_module::RUN_NON_BLOCKING_POSTSTART_COMMANDS_SCRIPT_NAME.to_sym =>
-        non_blocking_poststart_commands_script,
+        non_blocking_poststart_commands_script(user_command_ids: ["user-defined-command"]),
       "gl-sleep-until-container-is-running-command":
         sleep_until_container_is_running_script,
-      "gl-start-sshd-command": files::INTERNAL_POSTSTART_COMMAND_START_SSHD_SCRIPT
+      "gl-start-sshd-command": files::INTERNAL_POSTSTART_COMMAND_START_SSHD_SCRIPT,
+      "user-defined-command": "echo 'user-defined postStart command'"
     )
   end
 
diff --git a/ee/spec/requests/remote_development/integration_spec.rb b/ee/spec/requests/remote_development/integration_spec.rb
index 5c5186595da68ed2feae34159aa155c0f32783d4..f3a6d24c94a3765ce40bff259ac8ddf39dfb4afb 100644
--- a/ee/spec/requests/remote_development/integration_spec.rb
+++ b/ee/spec/requests/remote_development/integration_spec.rb
@@ -72,6 +72,19 @@
     ]
   end
 
+  let(:user_defined_commands) do
+    [
+      {
+        id: "user-defined-command",
+        exec: {
+          component: "tooling-container",
+          commandLine: "echo 'user-defined postStart command'",
+          hotReloadCapable: false
+        }
+      }
+    ]
+  end
+
   let(:namespace_agents_config_query) do
     <<~GRAPHQL
       query {
@@ -445,7 +458,8 @@ def do_reconcile_post(params:, agent_token:)
           dns_zone: dns_zone,
           namespace_path: workspace_project_namespace.full_path,
           project_name: workspace_project_name,
-          image_pull_secrets: image_pull_secrets
+          image_pull_secrets: image_pull_secrets,
+          user_defined_commands: user_defined_commands
         )
 
       # SIMULATE RECONCILE RESPONSE TO AGENTK SENDING NEW WORKSPACE
diff --git a/ee/spec/support/helpers/remote_development/integration_spec_helpers.rb b/ee/spec/support/helpers/remote_development/integration_spec_helpers.rb
index 2552049afb335c906eef9544ec1cb1ad62d1c340..d3843924a1610050b80dfb71ab275849a68ec372 100644
--- a/ee/spec/support/helpers/remote_development/integration_spec_helpers.rb
+++ b/ee/spec/support/helpers/remote_development/integration_spec_helpers.rb
@@ -9,20 +9,23 @@ module IntegrationSpecHelpers
     # @param [String] namespace_path
     # @param [String] project_name
     # @param [Array] image_pull_secrets
+    # @param [Array] user_defined_commands
     # @return [Hash]
     def build_additional_args_for_expected_config_to_apply_yaml_stream(
       network_policy_enabled:,
       dns_zone:,
       namespace_path:,
       project_name:,
-      image_pull_secrets:
+      image_pull_secrets:,
+      user_defined_commands:
     )
       {
         dns_zone: dns_zone,
         namespace_path: namespace_path,
         project_name: project_name,
         include_network_policy: network_policy_enabled,
-        image_pull_secrets: image_pull_secrets
+        image_pull_secrets: image_pull_secrets,
+        user_defined_commands: user_defined_commands
       }
     end
 
diff --git a/ee/spec/support/shared_contexts/remote_development/remote_development_shared_contexts.rb b/ee/spec/support/shared_contexts/remote_development/remote_development_shared_contexts.rb
index 4c00056d1f59641ab73682e259951f435027cfb0..5d667ba17665aa6a8fc8e58345300a937b8ec5e6 100644
--- a/ee/spec/support/shared_contexts/remote_development/remote_development_shared_contexts.rb
+++ b/ee/spec/support/shared_contexts/remote_development/remote_development_shared_contexts.rb
@@ -7,7 +7,7 @@
 
   # rubocop:todo Metrics/ParameterLists, Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity -- Cleanup as part of https://gitlab.com/gitlab-org/gitlab/-/issues/421687
 
-  # @return [Array]
+  # @return [Array<Hash>]
   def create_desired_config_array
     json_content = RemoteDevelopment::FixtureFileHelpers.read_fixture_file('example.desired_config.json')
     Gitlab::Json.parse(json_content).map(&:deep_symbolize_keys)
@@ -361,6 +361,8 @@ def create_config_to_apply(workspace:, **args)
   # @param [Array<Hash>] image_pull_secrets
   # @param [Boolean] include_scripts_resources
   # @param [Boolean] legacy_no_poststart_container_command
+  # @param [Boolean] legacy_poststart_container_command
+  # @param [Array<Hash>] user_defined_commands
   # @param [String] shared_namespace
   # @param [Boolean] core_resources_only
   # @return [Array<Hash>]
@@ -392,6 +394,7 @@ def create_config_to_apply_v3(
     include_scripts_resources: true,
     legacy_no_poststart_container_command: false,
     legacy_poststart_container_command: false,
+    user_defined_commands: [],
     shared_namespace: "",
     core_resources_only: false
   )
@@ -482,7 +485,8 @@ def create_config_to_apply_v3(
       workspace_namespace: workspace.namespace,
       labels: labels,
       annotations: workspace_inventory_annotations,
-      legacy_poststart_container_command: legacy_poststart_container_command
+      legacy_poststart_container_command: legacy_poststart_container_command,
+      user_defined_commands: user_defined_commands
     )
 
     secrets_inventory_config_map = secrets_inventory_config_map(
@@ -1175,15 +1179,27 @@ def internal_blocking_poststart_commands_script
     SCRIPT
   end
 
+  # @param [Array<String>] user_command_ids
   # @return [String]
-  def non_blocking_poststart_commands_script
-    <<~SCRIPT
+  def non_blocking_poststart_commands_script(user_command_ids: [])
+    script = <<~SCRIPT
       #!/bin/sh
       echo "$(date -Iseconds): Running #{reconcile_constants_module::WORKSPACE_SCRIPTS_VOLUME_PATH}/gl-sleep-until-container-is-running-command..."
       #{reconcile_constants_module::WORKSPACE_SCRIPTS_VOLUME_PATH}/gl-sleep-until-container-is-running-command || true
     SCRIPT
+
+    # Add user-defined commands if any
+    user_command_ids.each do |command_id|
+      script += <<~SCRIPT
+        echo "$(date -Iseconds): Running #{reconcile_constants_module::WORKSPACE_SCRIPTS_VOLUME_PATH}/#{command_id}..."
+        #{reconcile_constants_module::WORKSPACE_SCRIPTS_VOLUME_PATH}/#{command_id} || true
+      SCRIPT
+    end
+
+    script
   end
 
+  # @return [String]
   def legacy_poststart_commands_script
     <<~SCRIPT
       #!/bin/sh
@@ -1228,21 +1244,25 @@ def sleep_until_container_is_running_script
   # @param [Hash] labels
   # @param [Hash] annotations
   # @param [Boolean] legacy_poststart_container_command
+  # @param [Array<Hash>] user_defined_commands
   # @return [Hash]
   def scripts_configmap(
     workspace_name:,
     workspace_namespace:,
     labels:,
     annotations:,
-    legacy_poststart_container_command:
+    legacy_poststart_container_command:,
+    user_defined_commands:
   )
+    user_command_ids = user_defined_commands.pluck(:id)
+
     data = {
       "gl-clone-project-command": clone_project_script,
       "gl-init-tools-command": files_module::INTERNAL_POSTSTART_COMMAND_START_VSCODE_SCRIPT,
       reconcile_constants_module::RUN_INTERNAL_BLOCKING_POSTSTART_COMMANDS_SCRIPT_NAME.to_sym =>
         internal_blocking_poststart_commands_script,
       reconcile_constants_module::RUN_NON_BLOCKING_POSTSTART_COMMANDS_SCRIPT_NAME.to_sym =>
-        non_blocking_poststart_commands_script,
+        non_blocking_poststart_commands_script(user_command_ids: user_command_ids),
       "gl-sleep-until-container-is-running-command": sleep_until_container_is_running_script,
       "gl-start-sshd-command": files_module::INTERNAL_POSTSTART_COMMAND_START_SSHD_SCRIPT
     }
@@ -1254,6 +1274,11 @@ def scripts_configmap(
         legacy_poststart_commands_script
     end
 
+    # Add each user-defined command to the data hash
+    user_defined_commands.each do |cmd|
+      data[cmd[:id].to_sym] = cmd[:exec][:commandLine]
+    end
+
     {
       apiVersion: "v1",
       kind: "ConfigMap",
diff --git a/locale/gitlab.pot b/locale/gitlab.pot
index 5491d5e0338d29bf97b3d007d22997990629943c..ec2a1fc33d7a8e65c7b25d45d009cfeb120a39df 100644
--- a/locale/gitlab.pot
+++ b/locale/gitlab.pot
@@ -1710,6 +1710,9 @@ msgstr ""
 msgid "'%{template_name}' is unknown or invalid"
 msgstr ""
 
+msgid "'%{type}' command '%{command}' must specify a 'component'"
+msgstr ""
+
 msgid "'%{value}' days of inactivity must be greater than or equal to 90"
 msgstr ""
 
@@ -14990,6 +14993,9 @@ msgstr ""
 msgid "Command"
 msgstr ""
 
+msgid "Command '%{command}' must have one of the supported command types: %{supported_types}"
+msgstr ""
+
 msgid "Command id '%{command}' must not start with '%{prefix}'"
 msgstr ""
 
@@ -22409,6 +22415,9 @@ msgstr ""
 msgid "Development widget is not enabled for this work item type"
 msgstr ""
 
+msgid "Devfile size (%{current_size}) exceeds the maximum allowed size of %{max_size}"
+msgstr ""
+
 msgid "Device name"
 msgstr ""
 
@@ -46417,6 +46426,9 @@ msgstr ""
 msgid "Possible to override in each project."
 msgstr ""
 
+msgid "PostStart event references command '%{command}' which is not an exec command. Only exec commands are supported in postStart events"
+msgstr ""
+
 msgid "Postman collection"
 msgstr ""
 
@@ -49671,6 +49683,9 @@ msgstr ""
 msgid "Property 'dedicatedPod' of component '%{name}' is not yet supported"
 msgstr ""
 
+msgid "Property 'hotReloadCapable' for exec command '%{command}' must be false when specified"
+msgstr ""
+
 msgid "Protect"
 msgstr ""
 
@@ -65663,6 +65678,9 @@ msgstr ""
 msgid "Unsupported node type for alias: %{type}"
 msgstr ""
 
+msgid "Unsupported options '%{options}' for exec command '%{command}'. Only '%{supported_options}' are supported."
+msgstr ""
+
 msgid "Unsupported signature"
 msgstr ""