diff --git a/.github/dependabot.yml b/.github/dependabot.yml
index 252d54f4..1968779f 100644
--- a/.github/dependabot.yml
+++ b/.github/dependabot.yml
@@ -1,5 +1,20 @@
 version: 2
 
+# Every ecosystem groups its updates into a single PR. Splitting per package
+# means each ecosystem's lockfile (go.sum, package-lock.json, Cargo.lock) is
+# rewritten once per PR, so merging any one of them invalidates all the rest —
+# every sibling then rebases and re-runs the full ~15 minute CI matrix. The
+# 2026-08-10 batch opened 17 PRs for one weekly refresh.
+#
+# Grouping also keeps release trains together. The OpenTelemetry modules move
+# in lockstep, and npm families version-lock their own packages with exact peer
+# pins (typescript-checker@9.6.0 requires core@9.6.0, not ^9.6.0), so a partial
+# merge is an ERESOLVE failure waiting to happen.
+#
+# Majors are ignored everywhere below, so each group only ever carries patch and
+# minor updates. If one member of a group is bad, add it to that ecosystem's
+# ignore list rather than ungrouping the rest.
+
 updates:
   # Go server dependencies
   - package-ecosystem: gomod
@@ -13,6 +28,10 @@ updates:
       - dependencies
       - go
     open-pull-requests-limit: 10
+    groups:
+      go-dependencies:
+        patterns:
+          - "*"
     ignore:
       - dependency-name: "*"
         update-types: ["version-update:semver-major"]
@@ -29,18 +48,10 @@ updates:
       - dependencies
       - npm
     open-pull-requests-limit: 10
-    # These families version-lock their own packages with exact peer pins
-    # (e.g. typescript-checker@9.6.0 requires core@9.6.0, not ^9.6.0), so a
-    # PR-per-package split guarantees an ERESOLVE failure whenever only some
-    # of them are merged. Group each family into a single PR.
     groups:
-      stryker:
+      npm-dependencies:
         patterns:
-          - "@stryker-mutator/*"
-      vitest:
-        patterns:
-          - "vitest"
-          - "@vitest/*"
+          - "*"
     ignore:
       - dependency-name: "*"
         update-types: ["version-update:semver-major"]
@@ -57,6 +68,10 @@ updates:
       - dependencies
       - rust
     open-pull-requests-limit: 5
+    groups:
+      cargo-dependencies:
+        patterns:
+          - "*"
     ignore:
       - dependency-name: "*"
         update-types: ["version-update:semver-major"]
@@ -73,6 +88,10 @@ updates:
       - dependencies
       - ci
     open-pull-requests-limit: 5
+    groups:
+      actions-dependencies:
+        patterns:
+          - "*"
     ignore:
       - dependency-name: "*"
         update-types: ["version-update:semver-major"]