diff --git a/src/main/java/net/siegeln/cameleer/saas/provisioning/DockerTenantProvisioner.java b/src/main/java/net/siegeln/cameleer/saas/provisioning/DockerTenantProvisioner.java
index ee0852b..63720ab 100644
--- a/src/main/java/net/siegeln/cameleer/saas/provisioning/DockerTenantProvisioner.java
+++ b/src/main/java/net/siegeln/cameleer/saas/provisioning/DockerTenantProvisioner.java
@@ -40,16 +40,20 @@ public class DockerTenantProvisioner implements TenantProvisioner {
     public ProvisionResult provision(TenantProvisionRequest req) {
         String serverName = serverContainerName(req.slug());
         String uiName = uiContainerName(req.slug());
+        String tenantNetwork = tenantNetworkName(req.slug());
         String endpoint = "http://" + serverName + ":8081";
 
         try {
             pullIfMissing(props.serverImage());
             pullIfMissing(props.serverUiImage());
 
-            createServerContainer(req, serverName);
+            // Create isolated tenant network
+            ensureNetwork(tenantNetwork);
+
+            createServerContainer(req, serverName, tenantNetwork);
             docker.startContainerCmd(serverName).exec();
 
-            createUiContainer(req.slug(), uiName, serverName);
+            createUiContainer(req.slug(), uiName, serverName, tenantNetwork);
             docker.startContainerCmd(uiName).exec();
 
             if (!waitForHealth(serverName, 60)) {
@@ -90,6 +94,7 @@ public class DockerTenantProvisioner implements TenantProvisioner {
     public void remove(String slug) {
         removeContainer(uiContainerName(slug));
         removeContainer(serverContainerName(slug));
+        removeNetwork(tenantNetworkName(slug));
     }
 
     @Override
@@ -112,19 +117,17 @@ public class DockerTenantProvisioner implements TenantProvisioner {
         return "http://" + serverContainerName(slug) + ":8081";
     }
 
-    private void createServerContainer(TenantProvisionRequest req, String name) {
+    private void createServerContainer(TenantProvisionRequest req, String name, String tenantNetwork) {
         String slug = req.slug();
         String prefix = "/t/" + slug;
 
         // Traefik labels — need >10 entries, use HashMap
         var labels = new java.util.HashMap<String, String>();
         labels.put("traefik.enable", "true");
-        // Router: match /t/{slug}/api/* and /t/{slug}/actuator/*
         labels.put("traefik.http.routers.server-" + slug + ".rule",
             "PathPrefix(`" + prefix + "/api`) || PathPrefix(`" + prefix + "/actuator`)");
         labels.put("traefik.http.routers.server-" + slug + ".tls", "true");
         labels.put("traefik.http.routers.server-" + slug + ".priority", "10");
-        // Strip the /t/{slug} prefix so server sees /api/... and /actuator/...
         labels.put("traefik.http.middlewares.server-strip-" + slug + ".stripprefix.prefixes", prefix);
         labels.put("traefik.http.routers.server-" + slug + ".middlewares", "server-strip-" + slug);
         labels.put("traefik.http.services.server-" + slug + ".loadbalancer.server.port", "8081");
@@ -150,14 +153,15 @@ public class DockerTenantProvisioner implements TenantProvisioner {
             "CAMELEER_ROUTING_DOMAIN=" + props.publicHost(),
             "CAMELEER_ROUTING_MODE=path",
             "CAMELEER_JAR_STORAGE_PATH=/data/jars",
-            "CAMELEER_DOCKER_NETWORK=" + props.networkName(),
+            // Apps deployed by this server join the tenant network (isolated)
+            "CAMELEER_DOCKER_NETWORK=" + tenantNetwork,
             "CAMELEER_JAR_DOCKER_VOLUME=cameleer-jars-" + slug
         );
 
-        // Docker socket mount for app deployment within tenant server
+        // Primary network = tenant-isolated network
         HostConfig hostConfig = HostConfig.newHostConfig()
             .withRestartPolicy(RestartPolicy.unlessStoppedRestart())
-            .withNetworkMode(props.networkName())
+            .withNetworkMode(tenantNetwork)
             .withBinds(new Bind("/var/run/docker.sock", new Volume("/var/run/docker.sock")))
             .withGroupAdd(List.of("0"));
 
@@ -174,24 +178,31 @@ public class DockerTenantProvisioner implements TenantProvisioner {
                 .withStartPeriod(15_000_000_000L))
             .exec();
 
-        // Connect to traefik network with DNS alias
+        String containerId = resp.getId();
+
+        // Connect to shared services network (postgres, clickhouse, logto)
+        docker.connectToNetworkCmd()
+            .withNetworkId(props.networkName())
+            .withContainerId(containerId)
+            .withContainerNetwork(new ContainerNetwork().withAliases(List.of(name)))
+            .exec();
+
+        // Connect to traefik network for routing
         docker.connectToNetworkCmd()
             .withNetworkId(props.traefikNetwork())
-            .withContainerId(resp.getId())
+            .withContainerId(containerId)
             .withContainerNetwork(new ContainerNetwork().withAliases(List.of(name)))
             .exec();
     }
 
-    private void createUiContainer(String slug, String uiName, String serverName) {
+    private void createUiContainer(String slug, String uiName, String serverName, String tenantNetwork) {
         String prefix = "/t/" + slug;
 
         var labels = new java.util.HashMap<String, String>();
         labels.put("traefik.enable", "true");
-        // Router: catch-all for /t/{slug}/* (lower priority than server API)
         labels.put("traefik.http.routers.ui-" + slug + ".rule", "PathPrefix(`" + prefix + "`)");
         labels.put("traefik.http.routers.ui-" + slug + ".tls", "true");
         labels.put("traefik.http.routers.ui-" + slug + ".priority", "5");
-        // Strip /t/{slug} prefix so UI sees /
         labels.put("traefik.http.middlewares.ui-strip-" + slug + ".stripprefix.prefixes", prefix);
         labels.put("traefik.http.routers.ui-" + slug + ".middlewares", "ui-strip-" + slug);
         labels.put("traefik.http.services.ui-" + slug + ".loadbalancer.server.port", "80");
@@ -203,9 +214,10 @@ public class DockerTenantProvisioner implements TenantProvisioner {
             "API_URL=http://" + serverName + ":8081"
         );
 
+        // Primary network = tenant network (can reach server via DNS)
         HostConfig hostConfig = HostConfig.newHostConfig()
             .withRestartPolicy(RestartPolicy.unlessStoppedRestart())
-            .withNetworkMode(props.networkName());
+            .withNetworkMode(tenantNetwork);
 
         CreateContainerResponse resp = docker.createContainerCmd(props.serverUiImage())
             .withName(uiName)
@@ -214,6 +226,7 @@ public class DockerTenantProvisioner implements TenantProvisioner {
             .withHostConfig(hostConfig)
             .exec();
 
+        // Connect to traefik for routing
         docker.connectToNetworkCmd()
             .withNetworkId(props.traefikNetwork())
             .withContainerId(resp.getId())
@@ -269,6 +282,30 @@ public class DockerTenantProvisioner implements TenantProvisioner {
         } catch (NotFoundException ignored) {}
     }
 
+    private void ensureNetwork(String networkName) {
+        try {
+            docker.inspectNetworkCmd().withNetworkId(networkName).exec();
+            log.debug("Network '{}' already exists", networkName);
+        } catch (NotFoundException e) {
+            docker.createNetworkCmd()
+                .withName(networkName)
+                .withDriver("bridge")
+                .withInternal(true) // no external access — isolated
+                .exec();
+            log.info("Created isolated tenant network: {}", networkName);
+        }
+    }
+
+    private void removeNetwork(String networkName) {
+        try {
+            docker.removeNetworkCmd(networkName).exec();
+            log.info("Removed tenant network: {}", networkName);
+        } catch (NotFoundException ignored) {
+        } catch (Exception e) {
+            log.warn("Failed to remove network '{}': {}", networkName, e.getMessage());
+        }
+    }
+
     private String serverContainerName(String slug) {
         return "cameleer-server-" + slug;
     }
@@ -276,4 +313,8 @@ public class DockerTenantProvisioner implements TenantProvisioner {
     private String uiContainerName(String slug) {
         return "cameleer-server-ui-" + slug;
     }
+
+    private String tenantNetworkName(String slug) {
+        return "cameleer-tenant-" + slug;
+    }
 }