diff --git a/deploy/k8s/configmap.yaml b/deploy/k8s/configmap.yaml
index 81cc9fbd..7a0a5a7a 100644
--- a/deploy/k8s/configmap.yaml
+++ b/deploy/k8s/configmap.yaml
@@ -60,3 +60,11 @@ data:
 
   # Pipeline latency budget (ms) — Construction spec §2.5
   PIPELINE_LATENCY_BUDGET_MS: "5000"
+
+  # Ecto pool size for vav-pipeline (runtime.exs default 20). The DBaaS
+  # is an Aiven hobbyist-2 shared with Gitea and Aiven's own monitor;
+  # a pool of 20 fills its connection ceiling by itself (2026-10-15:
+  # refusals "remaining connection slots are reserved" for 24 h, one
+  # pool worker looping, Aiven's monitor refused). Ten is ample for a
+  # single replica.
+  POOL_SIZE: "10"