diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1ffefca5..0dd15f45 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -60,6 +60,29 @@ written while it was being built. See [RELEASING.md](RELEASING.md).
 - Pages an organiser has not published no longer appear in the hackathon's
   navigation. They are reached through Manage Pages, which has moved above
   Manage Voting.
+- Hackagon can now run against a Postgres it does not install — a managed cloud
+  database, or one an operator provisions. Set `postgresql.enabled` to `false`,
+  point `backend.config.database.host` and `keycloak.database.external.host` at
+  your server, and create the two databases yourself. Previously the chart
+  always addressed a server named after its own release, so there was no way to
+  reach anything else.
+- The database password can now be read from a Kubernetes Secret you already
+  hold, via `backend.config.database.existingSecret` and
+  `existingSecretPasswordKey` (and the equivalent keys under
+  `keycloak.database.external`). This is what a secret store or a Postgres
+  operator needs: it writes the credentials, the chart reads them, and nobody
+  has to copy a password into a values file.
+
+### Changed
+
+- The backend's database password is no longer written into a ConfigMap. The
+  chart puts it in a Secret — its own, or the one you named — and hands it to
+  the backend as an environment variable. Before, anyone able to list ConfigMaps
+  in the namespace could read the database password.
+- Fixed `keycloak.database.external.database` and `.user` being silently
+  ignored: the Keycloak chart calls them `name` and `username`, so a non-default
+  database name or user never reached Keycloak and it quietly used `keycloak`
+  for both. The values are now named to match and the setting takes effect.
 
 - A hackathon overview with no phase running no longer opens with "No phase is
   running" and a footnote saying the timeline follows the dates alone. The card
diff --git a/helm-chart/Chart.yaml b/helm-chart/Chart.yaml
index a262dfc5..65cb2299 100644
--- a/helm-chart/Chart.yaml
+++ b/helm-chart/Chart.yaml
@@ -6,7 +6,7 @@ type: application
 
 # The chart's own version. Bumped by hand when the chart changes, and
 # independent of the app: the CI publishes whatever it finds here.
-version: 0.4.0
+version: 0.5.0
 # The app release this chart deploys. A new app release does
 # not become deployable until someone points the chart at it.
 appVersion: "0.9.1"
diff --git a/helm-chart/templates/NOTES.txt b/helm-chart/templates/NOTES.txt
index 7a35c30b..97741ced 100644
--- a/helm-chart/templates/NOTES.txt
+++ b/helm-chart/templates/NOTES.txt
@@ -8,11 +8,17 @@ To get the generated frontend OIDC secrets, run:
   kubectl get secret {{ include "hackagon.fullname" . }}-frontend-secrets \
     -n {{ .Release.Namespace }} -o jsonpath='{.data.secrets\.yaml}' | base64 -d
 
-Passwords are set in your values files. Retrieve them with:
+The backend reads its database password from a Secret:
 
-  # Platform (hackagon) user password
-  kubectl get secret {{ include "hackagon.fullname" . }}-postgresql \
+  kubectl get secret {{ include "hackagon.backendDatabaseSecretName" . }} \
+    -n {{ .Release.Namespace }} -o jsonpath='{.data.{{ include "hackagon.backendDatabaseSecretKey" . }}}' | base64 -d
+{{- if .Values.postgresql.enabled }}
+
+The bundled postgres superuser password:
+
+  kubectl get secret {{ .Release.Name }}-postgresql \
     -n {{ .Release.Namespace }} -o jsonpath='{.data.postgres-password}' | base64 -d
+{{- end }}
 
 Check the status of your release:
 
diff --git a/helm-chart/templates/_helpers.tpl b/helm-chart/templates/_helpers.tpl
index 9976d882..5fc43455 100644
--- a/helm-chart/templates/_helpers.tpl
+++ b/helm-chart/templates/_helpers.tpl
@@ -132,6 +132,34 @@ PostgreSQL service name (bitnami chart names it <release>-postgresql)
 {{- printf "%s-postgresql" .Release.Name }}
 {{- end }}
 
+{{/*
+The postgres host the backend connects to. `backend.config.database.host` wins;
+empty falls back to the bundled subchart's service, which is where this chart
+puts postgres when `postgresql.enabled`. Rendered with `tpl`, like every other
+host value.
+*/}}
+{{- define "hackagon.backendDatabaseHost" -}}
+{{- $host := tpl (.Values.backend.config.database.host | default "") . }}
+{{- $host | default (include "hackagon.postgresqlServiceName" .) }}
+{{- end }}
+
+{{/*
+Secret holding the backend's database password. An `existingSecret` is used as
+given; otherwise the chart manages its own, so the password never lands in the
+backend ConfigMap either way.
+*/}}
+{{- define "hackagon.backendDatabaseSecretName" -}}
+{{- .Values.backend.config.database.existingSecret | default (printf "%s-backend-db" (include "hackagon.fullname" .)) }}
+{{- end }}
+
+{{/*
+Key within that Secret. The chart-managed Secret is written under the same key,
+so both paths read the same way.
+*/}}
+{{- define "hackagon.backendDatabaseSecretKey" -}}
+{{- .Values.backend.config.database.existingSecretPasswordKey | default "password" }}
+{{- end }}
+
 {{/*
 Get password: use provided value or generate one
 */}}
diff --git a/helm-chart/templates/backend-configmap.yaml b/helm-chart/templates/backend-configmap.yaml
index 5c4c559b..12aa4b2f 100644
--- a/helm-chart/templates/backend-configmap.yaml
+++ b/helm-chart/templates/backend-configmap.yaml
@@ -16,11 +16,14 @@ data:
       adminkeycloakid: {{ .Values.backend.config.server.adminkeycloakid | quote }}
     database:
       driver: {{ .Values.backend.config.database.driver | quote }}
-      host: {{ include "hackagon.postgresqlServiceName" . | quote }}
+      host: {{ include "hackagon.backendDatabaseHost" . | quote }}
       port: {{ .Values.backend.config.database.port }}
       dbname: {{ .Values.backend.config.database.dbname | quote }}
       user: {{ .Values.backend.config.database.user | quote }}
-      password: {{ .Values.backend.config.database.postgresPassword | required "postgresql.auth.postgresPassword is required" | quote }}
+      # No `password` here on purpose: a ConfigMap is world-readable to anything
+      # that can read the namespace. The backend reads it from the environment
+      # instead (HACKAGON_DATABASE_PASSWORD, set from a Secret in
+      # backend-deployment.yaml), which koanf layers over this file.
     oidc:
       jwksurl: {{ tpl .Values.backend.config.oidc.jwksurl . | quote }}
       issuerurl: {{ include "hackagon.oidcIssuer" . | quote }}
diff --git a/helm-chart/templates/backend-deployment.yaml b/helm-chart/templates/backend-deployment.yaml
index 9e499789..5ba593b3 100644
--- a/helm-chart/templates/backend-deployment.yaml
+++ b/helm-chart/templates/backend-deployment.yaml
@@ -30,6 +30,14 @@ spec:
           {{- end }}
           args:
             - "--config-dir=/etc/hackagon/"
+          env:
+            # Overrides `database.password` from the mounted config.yaml, which
+            # deliberately leaves it unset.
+            - name: HACKAGON_DATABASE_PASSWORD
+              valueFrom:
+                secretKeyRef:
+                  name: {{ include "hackagon.backendDatabaseSecretName" . }}
+                  key: {{ include "hackagon.backendDatabaseSecretKey" . }}
           ports:
             - name: grpc
               containerPort: 3000
diff --git a/helm-chart/templates/backend-postgres-secret.yaml b/helm-chart/templates/backend-postgres-secret.yaml
new file mode 100644
index 00000000..3d518c41
--- /dev/null
+++ b/helm-chart/templates/backend-postgres-secret.yaml
@@ -0,0 +1,13 @@
+{{- if not .Values.backend.config.database.existingSecret }}
+apiVersion: v1
+kind: Secret
+metadata:
+  name: {{ include "hackagon.backendDatabaseSecretName" . }}
+  namespace: {{ .Release.Namespace }}
+  labels:
+    {{- include "hackagon.labels" . | nindent 4 }}
+    app.kubernetes.io/component: backend
+type: Opaque
+stringData:
+  {{ include "hackagon.backendDatabaseSecretKey" . }}: {{ .Values.backend.config.database.postgresPassword | required "backend.config.database.postgresPassword is required unless backend.config.database.existingSecret is set" | quote }}
+{{- end }}
diff --git a/helm-chart/templates/keycloak-init-configmap.yaml b/helm-chart/templates/keycloak-init-configmap.yaml
index 78f2f04c..ffd74e93 100644
--- a/helm-chart/templates/keycloak-init-configmap.yaml
+++ b/helm-chart/templates/keycloak-init-configmap.yaml
@@ -1,3 +1,10 @@
+{{- if .Values.postgresql.enabled }}
+{{/*
+Bootstraps the roles and databases inside the postgres this chart installs. An
+external postgres is expected to have them already, so with
+`postgresql.enabled: false` this ConfigMap is not rendered at all and neither
+password has to be given to the chart in plaintext.
+*/}}
 apiVersion: v1
 kind: ConfigMap
 metadata:
@@ -7,9 +14,12 @@ metadata:
     {{- include "hackagon.labels" . | nindent 4 }}
 data:
   01-create-keycloak-db.sql: |
-    CREATE USER keycloak WITH PASSWORD '{{ .Values.keycloak.database.external.password | required "keycloak.database.external.password is required" }}';
-    CREATE DATABASE keycloak OWNER keycloak;
-    GRANT ALL PRIVILEGES ON DATABASE keycloak TO keycloak;
-    CREATE USER hackagon WITH PASSWORD '{{ .Values.backend.config.database.postgresPassword | required "backend.config.database.postgresPassword" }}';
-    CREATE DATABASE hackagon OWNER hackagon;
-    GRANT ALL PRIVILEGES ON DATABASE hackagon TO hackagon;
+    {{- if .Values.keycloak.enabled }}
+    CREATE USER {{ .Values.keycloak.database.external.username }} WITH PASSWORD '{{ .Values.keycloak.database.external.password }}';
+    CREATE DATABASE {{ .Values.keycloak.database.external.name }} OWNER {{ .Values.keycloak.database.external.username }};
+    GRANT ALL PRIVILEGES ON DATABASE {{ .Values.keycloak.database.external.name }} TO {{ .Values.keycloak.database.external.username }};
+    {{- end }}
+    CREATE USER {{ .Values.backend.config.database.user }} WITH PASSWORD '{{ .Values.backend.config.database.postgresPassword | required "backend.config.database.postgresPassword is required when postgresql.enabled is true" }}';
+    CREATE DATABASE {{ .Values.backend.config.database.dbname }} OWNER {{ .Values.backend.config.database.user }};
+    GRANT ALL PRIVILEGES ON DATABASE {{ .Values.backend.config.database.dbname }} TO {{ .Values.backend.config.database.user }};
+{{- end }}
diff --git a/helm-chart/templates/keycloak-realm-configmap.yaml b/helm-chart/templates/keycloak-realm-configmap.yaml
index a62204d6..54afa6fc 100644
--- a/helm-chart/templates/keycloak-realm-configmap.yaml
+++ b/helm-chart/templates/keycloak-realm-configmap.yaml
@@ -1,5 +1,3 @@
-{{- $host := .Values.keycloak.database.external.host | required "keycloak.database.external.host is required (e.g. \"hackagon-postgresql\")" -}}
-{{- $keycloakPassword := .Values.keycloak.database.external.password | required "keycloak.database.external.password is required" -}}
 apiVersion: v1
 kind: ConfigMap
 metadata:
diff --git a/helm-chart/templates/validations.yaml b/helm-chart/templates/validations.yaml
new file mode 100644
index 00000000..94a57270
--- /dev/null
+++ b/helm-chart/templates/validations.yaml
@@ -0,0 +1,32 @@
+{{/*
+Value combinations the chart cannot render. Deliberately produces no manifest;
+it exists so these failures are reported in one place with a usable message
+rather than as a `required` deep inside an unrelated template.
+*/}}
+
+{{- $db := .Values.backend.config.database }}
+
+{{/*
+The bundled postgres bootstraps its databases from an initdb SQL script, which
+is a ConfigMap: it can only be written with a password the chart can read.
+*/}}
+{{- if and .Values.postgresql.enabled $db.existingSecret }}
+  {{- fail "backend.config.database.existingSecret is set, but postgresql.enabled is true: the bundled postgres creates the hackagon role from an init script and cannot read a Secret. Either set backend.config.database.postgresPassword instead, or set postgresql.enabled=false and provision the database on your own postgres." }}
+{{- end }}
+
+{{- if and $db.existingSecret $db.postgresPassword }}
+  {{- fail "backend.config.database.existingSecret and backend.config.database.password cannot be set at the same time. Choose one." }}
+{{- end }}
+
+{{- if .Values.keycloak.enabled }}
+  {{- if and .Values.postgresql.enabled .Values.keycloak.database.external.existingSecret }}
+    {{- fail "keycloak.database.external.existingSecret is set, but postgresql.enabled is true: the bundled postgres creates the keycloak role from an init script and cannot read a Secret. Either set keycloak.database.external.password instead, or set postgresql.enabled=false and provision the database on your own postgres." }}
+  {{- end }}
+  {{- $_ := .Values.keycloak.database.external.host | required "keycloak.database.external.host is required (e.g. \"hackagon-postgresql\", or the hostname of an external postgres)" }}
+  {{- if not .Values.keycloak.database.external.existingSecret }}
+    {{- $_ := .Values.keycloak.database.external.password | required "keycloak.database.external.password is required unless keycloak.database.external.existingSecret is set" }}
+  {{- end }}
+  {{- if and .Values.keycloak.database.external.existingSecret .Values.keycloak.database.external.password }}
+    {{- fail "keycloak.database.external.existingSecret and keycloak.database.external.password cannot be set at the same time. Choose one." }}
+  {{- end }}
+{{- end }}
diff --git a/helm-chart/values.yaml b/helm-chart/values.yaml
index ec8728de..91613a82 100644
--- a/helm-chart/values.yaml
+++ b/helm-chart/values.yaml
@@ -118,11 +118,25 @@ backend:
       adminkeycloakid: ""
     database:
       driver: postgres
-      host: "" # Auto-generated from release name in template
+      # -- Postgres host the backend connects to. Empty falls back to the
+      # bundled subchart's service (`<release>-postgresql`). Set it to reach a
+      # postgres this chart does not manage — a managed provider, or one
+      # installed under a different release name. Rendered with `tpl`.
+      host: ""
       port: 5432
       dbname: hackagon
       user: hackagon
-      postgresPassword: ""
+      # -- Password for `user`. The chart puts it in a Secret of its own and
+      # injects it as an env var, never into the backend ConfigMap. 
+      postgresPassword: "" # Only use it existingSecret is empty
+      # -- Read the password from a Secret you already have instead of letting
+      # the chart manage one. Required by a postgres operator or an external
+      # secret store, which writes the credentials before the chart runs.
+      # Incompatible with `postgresql.enabled`: the bundled postgres bootstraps
+      # its roles from an init script and cannot read a Secret.
+      existingSecret: ""
+      # -- Key inside `existingSecret` holding the password.
+      existingSecretPasswordKey: password
     oidc:
       # -- Where the backend fetches Keycloak's signing keys.
       # With an external Keycloak (keycloak.enabled: false),
@@ -164,15 +178,26 @@ keycloak:
   admin:
     username: hackagon-admin
 
-  # -- External database (reuse the same postgres instance)
+  # -- External database. Points at the bundled postgres by default, but any
+  # reachable postgres works. These keys are passed to the keycloak subchart
+  # verbatim, so they must use its names (`name`/`username`, not
+  # `database`/`user`).
   database:
     external:
       vendor: postgres
-      host: "" # Required: set to <release>-postgresql (e.g. "hackagon-postgresql")
+      # -- Required: <release>-postgresql (e.g. "hackagon-postgresql") for the
+      # bundled postgres, otherwise the external host.
+      host: ""
       port: 5432
-      database: keycloak
-      user: keycloak
-      password: ""
+      name: keycloak
+      username: keycloak
+      password: "" # Only use it existingSecret is empty
+      # -- Read the password from a Secret you already have. Handled by the
+      # keycloak subchart. Incompatible with `postgresql.enabled`, for the same
+      # reason as the backend's.
+      existingSecret: ""
+      # -- Key inside `existingSecret` holding the password.
+      existingSecretPasswordKey: password
 
   # -- Realm import from ConfigMap
   realmImport:
@@ -211,11 +236,18 @@ keycloakIngress:
 # ============================================================
 # PostgreSQL (bitnami) — two databases, two users
 # ============================================================
+# Set `enabled: false` to run against a postgres this chart does not install.
+# Then create the `hackagon` and `keycloak` roles and databases yourself, point
+# `backend.config.database.host` and `keycloak.database.external.host` at it,
+# and supply the passwords — either directly or from existing Secrets.
 postgresql:
   enabled: true
   auth:
     username: postgres
     database: postgres
+    # -- The bitnami subchart also accepts `auth.existingSecret` together with
+    # `auth.secretKeys.adminPasswordKey`, if you would rather not put the
+    # superuser password in values.
     postgresPassword: ""
 
   primary: