diff --git a/docker-compose.portainer.staging.yml b/docker-compose.portainer.staging.yml
index c08ae48..99cc608 100644
--- a/docker-compose.portainer.staging.yml
+++ b/docker-compose.portainer.staging.yml
@@ -18,6 +18,10 @@
 #   TYPESENSE_SEARCH_KEY   — Typesense search-only key (exposed to frontend)
 #   UNLEASH_URL            — http://<unleash-ip>:4242/api (empty = all flags off)
 #   UNLEASH_API_TOKEN      — Unleash *client* token, environment: development
+#   PAYLOAD_SECRET         — Payload CMS encryption secret. REQUIRED: long and
+#                            random, and DIFFERENT from production's. Sharing
+#                            it would let a staging session authenticate
+#                            against production.
 #   AIRFLOW_ADMIN_USER     — Airflow admin username (default: admin)
 #   AIRFLOW_ADMIN_PASSWORD — Airflow admin password. REQUIRED: the api-server
 #                            refuses to start without it, rather than falling
@@ -89,9 +93,20 @@ services:
       - FASTAPI_URL=http://backend:80/api
       - TYPESENSE_URL=http://typesense:8108
       - TYPESENSE_API_KEY=${TYPESENSE_SEARCH_KEY:-changeme}
+      # Payload CMS runs inside this container, in the `payload` schema of the
+      # staging database. Staging has its own stack, its own Postgres and its
+      # own admin account — never production's.
+      - DATABASE_URL=postgresql://${DB_USERNAME}:${DB_PASSWORD}@sc_database:5432/${DB_DATABASE_NAME}
+      - PAYLOAD_SECRET=${PAYLOAD_SECRET:?set PAYLOAD_SECRET in the staging Portainer stack environment}
+    volumes:
+      # Portainer prefixes volume names with the stack name, so this is
+      # automatically isolated from production's media.
+      - payload_media:/app/media
     depends_on:
       backend:
         condition: service_healthy
+      sc_database:
+        condition: service_healthy
     networks:
       backend: {}
       macvlan:
@@ -242,3 +257,4 @@ volumes:
   typesense_data:
   airflow_logs:
   unleash_cache:
+  payload_media:
diff --git a/docker-compose.portainer.yml b/docker-compose.portainer.yml
index 00e085e..fd2be50 100644
--- a/docker-compose.portainer.yml
+++ b/docker-compose.portainer.yml
@@ -9,6 +9,9 @@
 #   TYPESENSE_SEARCH_KEY   — Typesense search-only key (exposed to frontend)
 #   UNLEASH_URL            — http://<unleash-ip>:4242/api (empty = all flags off)
 #   UNLEASH_API_TOKEN      — Unleash *client* token, environment: production
+#   PAYLOAD_SECRET         — Payload CMS encryption secret. REQUIRED: long and
+#                            random. Changing it invalidates every admin
+#                            session. Staging MUST use a different value.
 #   AIRFLOW_ADMIN_USER     — Airflow admin username (default: admin)
 #   AIRFLOW_ADMIN_PASSWORD — Airflow admin password. REQUIRED: the api-server
 #                            refuses to start without it, rather than falling
@@ -78,9 +81,21 @@ services:
       - FASTAPI_URL=http://backend:80/api
       - TYPESENSE_URL=http://typesense:8108
       - TYPESENSE_API_KEY=${TYPESENSE_SEARCH_KEY:-changeme}
+      # Payload CMS runs inside this container. It reaches Postgres over the
+      # `backend` network and keeps its tables in the `payload` schema, so no
+      # pipeline operation on `public` can touch blog content.
+      - DATABASE_URL=postgresql://${DB_USERNAME}:${DB_PASSWORD}@sc_database:5432/${DB_DATABASE_NAME}
+      # Same :? form as AIRFLOW_ADMIN_PASSWORD: refuse to start rather than
+      # boot with an empty secret and silently accept forged sessions.
+      - PAYLOAD_SECRET=${PAYLOAD_SECRET:?set PAYLOAD_SECRET in the Portainer stack environment}
+    volumes:
+      # Blog images. Not reproducible from the pipeline — must be backed up.
+      - payload_media:/app/media
     depends_on:
       backend:
         condition: service_healthy
+      sc_database:
+        condition: service_healthy
     networks:
       backend: {}
       macvlan:
@@ -231,3 +246,4 @@ volumes:
   typesense_data:
   airflow_logs:
   unleash_cache:
+  payload_media:
diff --git a/nextjs-app/Dockerfile b/nextjs-app/Dockerfile
index 2f4665f..af446c9 100644
--- a/nextjs-app/Dockerfile
+++ b/nextjs-app/Dockerfile
@@ -53,6 +53,13 @@ COPY --from=builder /app/.next/static ./.next/static
 # a miss here is a silent 500 on /opengraph-image, not a build failure.
 COPY --from=builder /app/assets ./assets
 
+# Payload writes uploads here, and the compose file mounts a named volume over
+# it. The directory must exist and be owned by the runtime user BEFORE the
+# mount: Docker seeds a fresh named volume from the image path, so a missing or
+# root-owned directory here makes every upload fail with EACCES at runtime,
+# long after the build passed. The chown below covers it.
+RUN mkdir -p /app/media
+
 # Set correct permissions
 RUN chown -R nextjs:nodejs /app