diff --git a/src/lib/measurements/__tests__/rollups.test.ts b/src/lib/measurements/__tests__/rollups.test.ts
index 305ad249f..104376630 100644
--- a/src/lib/measurements/__tests__/rollups.test.ts
+++ b/src/lib/measurements/__tests__/rollups.test.ts
@@ -52,6 +52,15 @@ vi.mock("@/lib/jobs/boss-instance", () => ({
   getGlobalBoss: () => mocks.getGlobalBossMock(),
 }));
 
+// v1.4.36 QA H3 — `ensureUserRollupsFresh` now annotates + console-
+// errors on populator failures so silent regressions show up in ops.
+// Mock the annotate boundary so the test can assert the meta payload.
+vi.mock("@/lib/logging/context", () => ({
+  annotate: vi.fn(),
+}));
+
+import { annotate } from "@/lib/logging/context";
+
 const {
   queryRaw,
   queryRawUnsafe,
@@ -281,6 +290,40 @@ describe("ensureUserRollupsFresh", () => {
     const result = await ensureUserRollupsFresh("user-1");
     expect(result.recomputed).toBe(false);
   });
+
+  it("annotates the failure when the inner recompute throws (H3)", async () => {
+    // Stale watermark — rollup older than the newest measurement so
+    // the inner recompute branch fires.
+    const rollupAt = new Date("2026-05-10T10:00:00.000Z");
+    const measurementAt = new Date("2026-05-10T12:00:00.000Z");
+    findFirst.mockResolvedValueOnce({ computedAt: rollupAt });
+    findFirstMeasurement.mockResolvedValueOnce({
+      updatedAt: measurementAt,
+      measuredAt: measurementAt,
+    });
+    // The recompute aggregate query throws — simulates a populator
+    // regression (pool exhausted, deadlock, etc).
+    queryRawUnsafe.mockRejectedValueOnce(new Error("deadlock detected"));
+
+    const consoleSpy = vi.spyOn(console, "error").mockImplementation(() => {});
+
+    const result = await ensureUserRollupsFresh("user-1");
+
+    // The read path still gets a clean `{ recomputed: false }`.
+    expect(result.recomputed).toBe(false);
+    // The annotate event fires with the documented shape so ops can
+    // spot the silent populator regression in the wide-event pipeline.
+    expect(annotate).toHaveBeenCalledWith({
+      meta: {
+        rollup_refresh_failed: true,
+        rollup_refresh_error: "deadlock detected",
+      },
+    });
+    // And the console.error fallback fires so the worker log path
+    // surfaces the failure even when there's no request context.
+    expect(consoleSpy).toHaveBeenCalled();
+    consoleSpy.mockRestore();
+  });
 });
 
 describe("enqueueBootTimeRollupBackfill", () => {
diff --git a/src/lib/measurements/rollups.ts b/src/lib/measurements/rollups.ts
index 1f488f2e5..66f73aa3a 100644
--- a/src/lib/measurements/rollups.ts
+++ b/src/lib/measurements/rollups.ts
@@ -30,6 +30,7 @@
  */
 import { prisma } from "@/lib/db";
 import { getGlobalBoss } from "@/lib/jobs/boss-instance";
+import { annotate } from "@/lib/logging/context";
 import type {
   MeasurementType,
   RollupGranularity,
@@ -616,8 +617,21 @@ export async function ensureUserRollupsFresh(
       to: new Date(),
     });
     return { recomputed: true };
-  } catch {
+  } catch (err) {
     // Best-effort — never block the read path on a populator failure.
+    // v1.4.36 QA H3 — surface the failure so ops can spot a silent
+    // populator regression. `annotate` is a no-op when there's no
+    // request context (worker calls, tests); `console.error` carries
+    // the same shape through the worker log pipeline so the regression
+    // is visible regardless of caller surface.
+    const message = err instanceof Error ? err.message : String(err);
+    annotate({
+      meta: {
+        rollup_refresh_failed: true,
+        rollup_refresh_error: message,
+      },
+    });
+    console.error("[rollups] ensureUserRollupsFresh failed:", message);
     return { recomputed: false };
   }
 }