diff --git a/backend/migrations/001_init.sql b/backend/migrations/001_init.sql
index 3f56509..ab066f1 100644
--- a/backend/migrations/001_init.sql
+++ b/backend/migrations/001_init.sql
@@ -8,7 +8,7 @@ CREATE TABLE IF NOT EXISTS nodes (
 CREATE TABLE IF NOT EXISTS domains (
   id SERIAL PRIMARY KEY,
   domain TEXT UNIQUE NOT NULL,
-  node_name TEXT NOT NULL,
+  node_name TEXT,
   status TEXT NOT NULL DEFAULT 'active',
   first_seen_at TIMESTAMPTZ DEFAULT now(),
   last_seen_at TIMESTAMPTZ DEFAULT now()
@@ -18,7 +18,7 @@ CREATE TABLE IF NOT EXISTS mailboxes (
   id SERIAL PRIMARY KEY,
   email_address TEXT UNIQUE NOT NULL,
   domain TEXT NOT NULL,
-  node_name TEXT NOT NULL,
+  node_name TEXT,
   status TEXT NOT NULL DEFAULT 'active',
   used_bytes BIGINT DEFAULT 0,
   last_usage_scan_at TIMESTAMPTZ,
@@ -53,6 +53,12 @@ ALTER TABLE nodes
 ALTER TABLE nodes
   ADD COLUMN IF NOT EXISTS is_current BOOLEAN DEFAULT false;
 
+ALTER TABLE domains
+  ADD COLUMN IF NOT EXISTS node_name TEXT;
+
+ALTER TABLE domains
+  ADD COLUMN IF NOT EXISTS current_node TEXT;
+
 ALTER TABLE domains
   ADD COLUMN IF NOT EXISTS updated_at TIMESTAMPTZ DEFAULT now();
 
@@ -62,6 +68,9 @@ ALTER TABLE domains
 ALTER TABLE domains
   ADD COLUMN IF NOT EXISTS notes TEXT DEFAULT '';
 
+ALTER TABLE mailboxes
+  ADD COLUMN IF NOT EXISTS node_name TEXT;
+
 ALTER TABLE mailboxes
   ADD COLUMN IF NOT EXISTS local_part TEXT;
 
@@ -107,14 +116,69 @@ ALTER TABLE audit_log
 ALTER TABLE audit_log
   ALTER COLUMN details SET DEFAULT '{}';
 
--- Fill local_part for existing rows
+-- ============================================================
+-- Compatibility backfills
+-- ============================================================
+
+-- If an earlier version used current_node instead of node_name, copy it.
+DO $$
+BEGIN
+  IF EXISTS (
+    SELECT 1
+    FROM information_schema.columns
+    WHERE table_schema = 'public'
+      AND table_name = 'domains'
+      AND column_name = 'current_node'
+  ) THEN
+    EXECUTE '
+      UPDATE domains
+      SET node_name = current_node
+      WHERE node_name IS NULL
+        AND current_node IS NOT NULL
+    ';
+  END IF;
+END $$;
+
+-- If node_name is still empty, set it to current app node from env when available.
+DO $$
+DECLARE
+  app_node_name TEXT;
+BEGIN
+  app_node_name := current_setting('app.node_name', true);
+
+  IF app_node_name IS NOT NULL AND app_node_name <> '' THEN
+    UPDATE domains
+    SET node_name = app_node_name
+    WHERE node_name IS NULL;
+
+    UPDATE mailboxes
+    SET node_name = app_node_name
+    WHERE node_name IS NULL;
+  END IF;
+END $$;
+
+-- Fill current_node from node_name for compatibility with newer code variants.
+UPDATE domains
+SET current_node = node_name
+WHERE current_node IS NULL
+  AND node_name IS NOT NULL;
+
+-- Fill local_part for existing rows.
 UPDATE mailboxes
 SET local_part = split_part(email_address, '@', 1)
 WHERE local_part IS NULL
   AND email_address LIKE '%@%';
 
+-- Fill mailbox node_name from domain node_name where possible.
+UPDATE mailboxes m
+SET node_name = d.node_name
+FROM domains d
+WHERE m.domain = d.domain
+  AND m.node_name IS NULL
+  AND d.node_name IS NOT NULL;
+
 -- Keep old and new usage timestamp columns in sync initially.
--- This must be guarded because older/newer MVP databases may not have last_usage_scan_at.
+-- Dynamic EXECUTE is important here, otherwise PostgreSQL may still parse a missing column.
 DO $$
 BEGIN
   IF EXISTS (
@@ -124,15 +188,16 @@ BEGIN
       AND table_name = 'mailboxes'
       AND column_name = 'last_usage_scan_at'
   ) THEN
-    UPDATE mailboxes
-    SET usage_scanned_at = last_usage_scan_at
-    WHERE usage_scanned_at IS NULL
-      AND last_usage_scan_at IS NOT NULL;
+    EXECUTE '
+      UPDATE mailboxes
+      SET usage_scanned_at = last_usage_scan_at
+      WHERE usage_scanned_at IS NULL
+        AND last_usage_scan_at IS NOT NULL
+    ';
   END IF;
 END $$;
 
 -- Backfill new audit target columns from old target column.
--- This must also be guarded because some installations may already use target_id only.
 DO $$
 BEGIN
   IF EXISTS (
@@ -142,10 +207,12 @@ BEGIN
       AND table_name = 'audit_log'
       AND column_name = 'target'
   ) THEN
-    UPDATE audit_log
-    SET target_id = target
-    WHERE target_id IS NULL
-      AND target IS NOT NULL;
+    EXECUTE '
+      UPDATE audit_log
+      SET target_id = target
+      WHERE target_id IS NULL
+        AND target IS NOT NULL
+    ';
   END IF;
 END $$;
 
@@ -153,10 +220,40 @@ UPDATE audit_log
 SET target_type = 'unknown'
 WHERE target_type IS NULL;
 
+-- ============================================================
+-- Final constraints/defaults after backfill
+-- ============================================================
+
+ALTER TABLE domains
+  ALTER COLUMN node_name SET DEFAULT 'unknown';
+
+ALTER TABLE mailboxes
+  ALTER COLUMN node_name SET DEFAULT 'unknown';
+
+UPDATE domains
+SET node_name = 'unknown'
+WHERE node_name IS NULL;
+
+UPDATE mailboxes
+SET node_name = 'unknown'
+WHERE node_name IS NULL;
+
+ALTER TABLE domains
+  ALTER COLUMN node_name SET NOT NULL;
+
+ALTER TABLE mailboxes
+  ALTER COLUMN node_name SET NOT NULL;
+
+-- ============================================================
 -- Useful indexes
+-- ============================================================
+
 CREATE INDEX IF NOT EXISTS idx_domains_node_name
   ON domains(node_name);
 
+CREATE INDEX IF NOT EXISTS idx_domains_current_node
+  ON domains(current_node);
+
 CREATE INDEX IF NOT EXISTS idx_mailboxes_domain
   ON mailboxes(domain);