diff --git a/.ai/lessons.md b/.ai/lessons.md
index 33185493cb..c15a0558ec 100644
--- a/.ai/lessons.md
+++ b/.ai/lessons.md
@@ -45,6 +45,8 @@
 
 - MCP tools that call REST routes remove response keys from `BuildsResponse::$sensitiveKeys` (for example `content`, `client_id`, `logs`) when the token has no `read:sensitive`, and `CallsRestApi::$blockedRestPaths` blocks some routes. Check both lists when you name the fields of a new API response or add an MCP tool for a route.
 
+- To prove BuildKit cache behavior, use a new Dockerfile with a unique step for each experiment and repeat each build. Old cache records can make a changed input look cached. BuildKit keys `RUN` steps on the `--add-host` names and their order, but not on the IPs.
+
 ## Verify the complete user flow
 - Do not use a passing unit test, a successful build, or a healthy process as proof for a reported UI failure.
 - Verify the exact live flow, persisted state, relevant logs, and queue state when they affect the result.
diff --git a/app/Jobs/ApplicationDeploymentJob.php b/app/Jobs/ApplicationDeploymentJob.php
index 5c51791e5d..8a92fa8463 100644
--- a/app/Jobs/ApplicationDeploymentJob.php
+++ b/app/Jobs/ApplicationDeploymentJob.php
@@ -68,6 +68,12 @@ class ApplicationDeploymentJob implements ShouldBeEncrypted, ShouldQueue
      */
     private const HELPER_DOCKER_CONFIG = '/root/.docker';
 
+    /**
+     * Name prefixes of the helpers that DatabaseBackupJob (S3 upload) and StartDatabaseImport
+     * (S3 download) run on a resource network for the duration of one backup or import.
+     */
+    private const TEMPORARY_HELPER_CONTAINER_PREFIXES = ['backup-of-', 's3-restore-'];
+
     /**
      * System CA bundles of the supported server distributions, in the order that Go checks them.
      *
@@ -363,9 +369,11 @@ class ApplicationDeploymentJob implements ShouldBeEncrypted, ShouldQueue
     /**
      * Build the --add-host flags for the containers on the destination network.
      *
-     * Build helper containers are named after their deployment uuid and only live for the
-     * duration of that deployment. BuildKit keys every RUN layer on the --add-host set,
-     * so letting one in gives the next build a different set and forces a full rebuild.
+     * BuildKit keys every RUN layer on the host names of the --add-host set (not on the IPs), so a
+     * container that joins or leaves the network between two builds forces a full rebuild. The set
+     * leaves out the short-lived containers: build helpers (named after their deployment uuid),
+     * rolling update containers, and the backup and S3 import helpers. It also leaves out the proxy,
+     * Sentinel, and the proxy error page containers: no build uses them, and Coolify recreates them.
      */
     private function addHostFlags(Collection $containers): string
     {
@@ -377,7 +385,7 @@ class ApplicationDeploymentJob implements ShouldBeEncrypted, ShouldQueue
         $ips = collect([]);
         foreach ($containers as $container) {
             $containerName = data_get($container, 'Name');
-            if ($containerName === 'coolify-proxy') {
+            if (in_array($containerName, ['coolify-proxy', 'coolify-sentinel', Server::PROXY_ERROR_PAGE_CONTAINER], true)) {
                 continue;
             }
             if (isGeneratedContainerName($containerName)) {
@@ -386,6 +394,9 @@ class ApplicationDeploymentJob implements ShouldBeEncrypted, ShouldQueue
             if ($buildHelperNames->contains($containerName)) {
                 continue;
             }
+            if (str($containerName)->startsWith(self::TEMPORARY_HELPER_CONTAINER_PREFIXES)) {
+                continue;
+            }
             $containerIp = data_get($container, 'IPv4Address');
             if ($containerName && $containerIp) {
                 $ips->put($containerName, str($containerIp)->before('/')->value());
diff --git a/tests/Feature/ApplicationDeploymentAddHostsTest.php b/tests/Feature/ApplicationDeploymentAddHostsTest.php
index f57ac02e35..ef345e8f10 100644
--- a/tests/Feature/ApplicationDeploymentAddHostsTest.php
+++ b/tests/Feature/ApplicationDeploymentAddHostsTest.php
@@ -34,3 +34,23 @@ it('keeps the --add-host set stable whether or not a build helper is running', f
         ->toBe(addHostFlagsFor([$database]))
         ->toBe('--add-host postgres-main:10.0.1.3');
 });
+
+it('keeps database backup and S3 import helpers out of --add-host', function () {
+    $database = ['Name' => 'postgres-main', 'IPv4Address' => '10.0.1.3/24'];
+
+    expect(addHostFlagsFor([
+        $database,
+        ['Name' => 'backup-of-bk7f2c9d0a1e4b5c6d7e8f9a0', 'IPv4Address' => '10.0.1.11/24'],
+        ['Name' => 's3-restore-k4b2x9q1', 'IPv4Address' => '10.0.1.12/24'],
+    ]))->toBe(addHostFlagsFor([$database]))
+        ->toBe('--add-host postgres-main:10.0.1.3');
+});
+
+it('keeps the Coolify proxy, Sentinel, and error page containers out of --add-host', function () {
+    expect(addHostFlagsFor([
+        ['Name' => 'coolify-proxy', 'IPv4Address' => '10.0.1.2/24'],
+        ['Name' => 'coolify-sentinel', 'IPv4Address' => '10.0.1.3/24'],
+        ['Name' => 'coolify-proxy-error-pages', 'IPv4Address' => '10.0.1.4/24'],
+        ['Name' => 'postgres-main', 'IPv4Address' => '10.0.1.5/24'],
+    ]))->toBe('--add-host postgres-main:10.0.1.5');
+});