diff --git a/apps/backend/app/intelligence/query_service.py b/apps/backend/app/intelligence/query_service.py
index daa52987..da3e3666 100644
--- a/apps/backend/app/intelligence/query_service.py
+++ b/apps/backend/app/intelligence/query_service.py
@@ -83,7 +83,7 @@ class ArchitectureSnapshotFacts:
 
     snapshot: RiSnapshot
     nodes: list[RiNode]
-    #: Stable keys of every ``symbol`` node in the snapshot, and nothing else.
+    #: Stable keys of top-level ``symbol`` definitions used by module inventory.
     #: The architecture consumer needs to know what each file defines, but
     #: whole symbol rows are what dominate a large snapshot -- see the bound in
     #: ``architecture_facts``. Keys alone are short strings and carry the file
@@ -391,10 +391,16 @@ def architecture_facts(self, repository_id: str) -> ArchitectureSnapshotFacts |
         # that symbol is an endpoint of a relationship edge. Symbols dominate a
         # large snapshot, so excluding the unreferenced ones is the bound that
         # matters here — while still returning every node the consumer reads.
-        endpoint_keys = {key for edge in edges for key in (edge.subject_key, edge.object_key)}
-        node_filter = RiNode.node_kind.in_(ARCHITECTURE_NODE_KINDS)
-        if endpoint_keys:
-            node_filter = or_(node_filter, RiNode.stable_key.in_(endpoint_keys))
+        # Keep endpoint membership in SQL: a large graph must not become one
+        # bind parameter per endpoint (SQLite/PostgreSQL parameter limits).
+        endpoint_filter = (
+            RiEdge.snapshot_id == snapshot.snapshot_id,
+            RiEdge.predicate.in_(ARCHITECTURE_FACT_PREDICATES),
+        )
+        endpoint_keys = (
+            select(RiEdge.subject_key).where(*endpoint_filter).union(select(RiEdge.object_key).where(*endpoint_filter))
+        )
+        node_filter = or_(RiNode.node_kind.in_(ARCHITECTURE_NODE_KINDS), RiNode.stable_key.in_(endpoint_keys))
         nodes = list(
             self.db.scalars(
                 select(RiNode)
@@ -402,10 +408,25 @@ def architecture_facts(self, repository_id: str) -> ArchitectureSnapshotFacts |
                 .order_by(RiNode.stable_key, RiNode.id)
             ).all()
         )
+        # Module inventory only counts top-level definitions. Apply the same
+        # qualified-name rule as ArchitectureAnalyzer before materializing keys;
+        # nested methods dominate many real repositories and are never rendered.
+        delimiter = (
+            func.strpos(RiNode.stable_key, "::")
+            if self.db.get_bind().dialect.name == "postgresql"
+            else func.instr(RiNode.stable_key, "::")
+        )
+        qualified_name = func.substr(RiNode.stable_key, delimiter + 2)
         symbol_keys = list(
             self.db.scalars(
                 select(RiNode.stable_key)
-                .where(RiNode.snapshot_id == snapshot.snapshot_id, RiNode.node_kind == "symbol")
+                .where(
+                    RiNode.snapshot_id == snapshot.snapshot_id,
+                    RiNode.node_kind == "symbol",
+                    delimiter > 1,
+                    qualified_name != "",
+                    qualified_name.not_like("%.%"),
+                )
                 .order_by(RiNode.stable_key)
             ).all()
         )
diff --git a/apps/backend/tests/test_architecture_relationships.py b/apps/backend/tests/test_architecture_relationships.py
index 337f1b96..908f3533 100644
--- a/apps/backend/tests/test_architecture_relationships.py
+++ b/apps/backend/tests/test_architecture_relationships.py
@@ -582,3 +582,55 @@ def test_repository_furniture_does_not_become_an_architecture_module(auth_client
     # And nothing is left describing itself by its own path.
     assert not any("derived from repository intelligence" in node["description"] for node in architecture["nodes"])
     assert not any("Owns unknown concerns" in node["responsibilities"] for node in architecture["nodes"])
+
+
+def test_architecture_endpoint_membership_uses_a_bounded_sql_subquery(auth_client):
+    from sqlalchemy import event
+    from app.core.database import SessionLocal
+
+    sources = {
+        "src/alpha.ts": b"import { beta } from './beta';\nexport const alpha = beta;\n",
+        "src/beta.ts": b"export const beta = 1;\n",
+    }
+    repository = _upload(auth_client, sources)
+    _persist_snapshot(repository["id"], sources)
+    observed = []
+    with SessionLocal() as session:
+        record = session.get(RepositoryRecord, repository["id"])
+        engine = session.get_bind()
+
+        def capture(connection, cursor, statement, parameters, context, executemany):
+            if "ri_nodes" in statement and "UNION" in statement:
+                observed.append((statement, len(parameters)))
+
+        event.listen(engine, "before_cursor_execute", capture)
+        try:
+            facts = SnapshotQueryService(session, record.owner_id).architecture_facts(record.id)
+        finally:
+            event.remove(engine, "before_cursor_execute", capture)
+    assert facts is not None
+    assert observed
+    assert max(count for _, count in observed) < 50
+    endpoint_keys = {key for edge in facts.edges for key in (edge.subject_key, edge.object_key)}
+    assert endpoint_keys <= {node.stable_key for node in facts.nodes}
+
+
+def test_architecture_inventory_does_not_materialize_nested_method_keys(auth_client):
+    from app.core.database import SessionLocal
+
+    source = (
+        "export class LargeClass {\n"
+        + "".join(f"  method_{index}() {{ return {index}; }}\n" for index in range(500))
+        + "}\n"
+    )
+    sources = {"src/large.ts": source.encode()}
+    repository = _upload(auth_client, sources)
+    _persist_snapshot(repository["id"], sources)
+    with SessionLocal() as session:
+        record = session.get(RepositoryRecord, repository["id"])
+        facts = SnapshotQueryService(session, record.owner_id).architecture_facts(record.id)
+    assert facts is not None
+    assert facts.symbol_keys == ["src/large.ts::LargeClass"]
+    response = auth_client.get(f"/analysis/{repository['id']}/architecture")
+    assert response.status_code == 200
+    assert "Defines 1 symbol: LargeClass" in response.text