diff --git a/extensions/qa-lab/src/suite-summary.ts b/extensions/qa-lab/src/suite-summary.ts
index 8a4845d2d39..78d073772fb 100644
--- a/extensions/qa-lab/src/suite-summary.ts
+++ b/extensions/qa-lab/src/suite-summary.ts
@@ -23,6 +23,13 @@ export type QaSuiteSummaryJson = {
     gatewayProcessRssStartBytes?: number | null;
     gatewayProcessRssEndBytes?: number | null;
     gatewayProcessRssDeltaBytes?: number | null;
+    gatewayProcessRssPeakBytes?: number | null;
+    gatewayProcessRssPeakDeltaBytes?: number | null;
+    gatewayProcessRssSamples?: Array<{
+      label: string;
+      at: string;
+      gatewayProcessRssBytes: number;
+    }>;
   };
   run: {
     startedAt: string;
diff --git a/extensions/qa-lab/src/suite.summary-json.test.ts b/extensions/qa-lab/src/suite.summary-json.test.ts
index dead9540c7d..d731af797f2 100644
--- a/extensions/qa-lab/src/suite.summary-json.test.ts
+++ b/extensions/qa-lab/src/suite.summary-json.test.ts
@@ -156,6 +156,20 @@ describe("buildQaSuiteSummaryJson", () => {
         gatewayProcessRssStartBytes: 100_000_000,
         gatewayProcessRssEndBytes: 125_000_000,
         gatewayProcessRssDeltaBytes: 25_000_000,
+        gatewayProcessRssPeakBytes: 140_000_000,
+        gatewayProcessRssPeakDeltaBytes: 40_000_000,
+        gatewayProcessRssSamples: [
+          {
+            label: "suite-start",
+            at: "2026-04-22T12:00:00.000Z",
+            gatewayProcessRssBytes: 100_000_000,
+          },
+          {
+            label: "scenario:canary:finish",
+            at: "2026-04-22T12:00:10.000Z",
+            gatewayProcessRssBytes: 140_000_000,
+          },
+        ],
       },
     });
     expect(json.metrics).toEqual({
@@ -165,6 +179,20 @@ describe("buildQaSuiteSummaryJson", () => {
       gatewayProcessRssStartBytes: 100_000_000,
       gatewayProcessRssEndBytes: 125_000_000,
       gatewayProcessRssDeltaBytes: 25_000_000,
+      gatewayProcessRssPeakBytes: 140_000_000,
+      gatewayProcessRssPeakDeltaBytes: 40_000_000,
+      gatewayProcessRssSamples: [
+        {
+          label: "suite-start",
+          at: "2026-04-22T12:00:00.000Z",
+          gatewayProcessRssBytes: 100_000_000,
+        },
+        {
+          label: "scenario:canary:finish",
+          at: "2026-04-22T12:00:10.000Z",
+          gatewayProcessRssBytes: 140_000_000,
+        },
+      ],
     });
   });
 });
diff --git a/extensions/qa-lab/src/suite.test.ts b/extensions/qa-lab/src/suite.test.ts
index f332b4c5c82..11260f3953f 100644
--- a/extensions/qa-lab/src/suite.test.ts
+++ b/extensions/qa-lab/src/suite.test.ts
@@ -137,6 +137,52 @@ describe("qa suite", () => {
     expect(qaSuiteProgressTesting.sanitizeQaSuiteProgressValue("\u0000\u0001")).toBe("<empty>");
   });
 
+  it("records gateway RSS peak and trace samples", () => {
+    expect(
+      qaSuiteProgressTesting.buildQaSuiteRuntimeMetrics({
+        startedAt: new Date("2026-04-22T12:00:00.000Z"),
+        finishedAt: new Date("2026-04-22T12:00:12.000Z"),
+        gatewayProcessCpuStartMs: 1_000,
+        gatewayProcessCpuEndMs: 4_000,
+        gatewayProcessRssStartBytes: 100_000_000,
+        gatewayProcessRssEndBytes: 125_000_000,
+        gatewayProcessRssSamples: [
+          {
+            label: "suite-start",
+            at: "2026-04-22T12:00:00.000Z",
+            gatewayProcessRssBytes: 100_000_000,
+          },
+          {
+            label: "scenario:canary:finish",
+            at: "2026-04-22T12:00:10.000Z",
+            gatewayProcessRssBytes: 140_000_000,
+          },
+        ],
+      }),
+    ).toEqual({
+      wallMs: 12_000,
+      gatewayProcessCpuMs: 3_000,
+      gatewayCpuCoreRatio: 0.25,
+      gatewayProcessRssStartBytes: 100_000_000,
+      gatewayProcessRssEndBytes: 125_000_000,
+      gatewayProcessRssDeltaBytes: 25_000_000,
+      gatewayProcessRssPeakBytes: 140_000_000,
+      gatewayProcessRssPeakDeltaBytes: 40_000_000,
+      gatewayProcessRssSamples: [
+        {
+          label: "suite-start",
+          at: "2026-04-22T12:00:00.000Z",
+          gatewayProcessRssBytes: 100_000_000,
+        },
+        {
+          label: "scenario:canary:finish",
+          at: "2026-04-22T12:00:10.000Z",
+          gatewayProcessRssBytes: 140_000_000,
+        },
+      ],
+    });
+  });
+
   it("builds a codex mock runtime env patch that stays on the QA mock provider", () => {
     expect(
       qaSuiteProgressTesting.buildQaRuntimeEnvPatch({
diff --git a/extensions/qa-lab/src/suite.ts b/extensions/qa-lab/src/suite.ts
index 890f4226331..0d75ecb6d94 100644
--- a/extensions/qa-lab/src/suite.ts
+++ b/extensions/qa-lab/src/suite.ts
@@ -450,6 +450,10 @@ export type QaSuiteSummaryJsonParams = {
  */
 export type { QaSuiteSummaryJson } from "./suite-summary.js";
 
+type QaSuiteGatewayRssSample = NonNullable<
+  NonNullable<QaSuiteSummaryJson["metrics"]>["gatewayProcessRssSamples"]
+>[number];
+
 /**
  * Pure-ish JSON builder for qa-suite-summary.json. Exported so the GPT-5.5
  * parity gate (agentic-parity-report.ts, #64441) and any future parity
@@ -762,8 +766,16 @@ function buildQaSuiteRuntimeMetrics(params: {
   gatewayProcessCpuEndMs: number | null;
   gatewayProcessRssStartBytes: number | null;
   gatewayProcessRssEndBytes: number | null;
+  gatewayProcessRssSamples?: QaSuiteGatewayRssSample[];
 }): QaSuiteSummaryJson["metrics"] {
   const wallMs = Math.max(1, params.finishedAt.getTime() - params.startedAt.getTime());
+  const gatewayProcessRssSamples = params.gatewayProcessRssSamples ?? [];
+  const gatewayProcessRssPeakBytes =
+    gatewayProcessRssSamples.length > 0
+      ? Math.max(...gatewayProcessRssSamples.map((sample) => sample.gatewayProcessRssBytes))
+      : params.gatewayProcessRssStartBytes === null || params.gatewayProcessRssEndBytes === null
+        ? null
+        : Math.max(params.gatewayProcessRssStartBytes, params.gatewayProcessRssEndBytes);
   const rssMetrics =
     params.gatewayProcessRssStartBytes === null || params.gatewayProcessRssEndBytes === null
       ? {}
@@ -772,6 +784,16 @@ function buildQaSuiteRuntimeMetrics(params: {
           gatewayProcessRssEndBytes: params.gatewayProcessRssEndBytes,
           gatewayProcessRssDeltaBytes:
             params.gatewayProcessRssEndBytes - params.gatewayProcessRssStartBytes,
+          ...(gatewayProcessRssPeakBytes === null
+            ? {}
+            : {
+                gatewayProcessRssPeakBytes,
+                gatewayProcessRssPeakDeltaBytes:
+                  gatewayProcessRssPeakBytes - params.gatewayProcessRssStartBytes,
+              }),
+          ...(gatewayProcessRssSamples.length === 0
+            ? {}
+            : { gatewayProcessRssSamples }),
         };
   if (params.gatewayProcessCpuStartMs === null || params.gatewayProcessCpuEndMs === null) {
     return { wallMs, ...rssMetrics };
@@ -1196,14 +1218,27 @@ export async function runQaSuite(params?: QaSuiteRunParams): Promise<QaSuiteResu
       scenarios: liveScenarioOutcomes,
     });
 
+    const gatewayProcessRssSamples: QaSuiteGatewayRssSample[] = [];
+    const sampleGatewayProcessRss = (label: string) => {
+      const gatewayProcessRssBytes = gateway.getProcessRssBytes?.() ?? null;
+      if (gatewayProcessRssBytes !== null) {
+        gatewayProcessRssSamples.push({
+          label,
+          at: new Date().toISOString(),
+          gatewayProcessRssBytes,
+        });
+      }
+      return gatewayProcessRssBytes;
+    };
     const gatewayProcessCpuStartMs = gateway.getProcessCpuMs?.() ?? null;
-    const gatewayProcessRssStartBytes = gateway.getProcessRssBytes?.() ?? null;
+    const gatewayProcessRssStartBytes = sampleGatewayProcessRss("suite-start");
     for (const [index, scenario] of selectedCatalogScenarios.entries()) {
       const scenarioIdForLog = sanitizeQaSuiteProgressValue(scenario.id);
       writeQaSuiteProgress(
         progressEnabled,
         `scenario start (${index + 1}/${selectedCatalogScenarios.length}): ${scenarioIdForLog}`,
       );
+      sampleGatewayProcessRss(`scenario:${scenario.id}:start`);
       liveScenarioOutcomes[index] = {
         id: scenario.id,
         name: scenario.title,
@@ -1218,6 +1253,7 @@ export async function runQaSuite(params?: QaSuiteRunParams): Promise<QaSuiteResu
       });
 
       const result = await runScenarioDefinition(env, scenario);
+      sampleGatewayProcessRss(`scenario:${scenario.id}:finish`);
       scenarios.push(result);
       writeQaSuiteProgress(
         progressEnabled,
@@ -1260,7 +1296,8 @@ export async function runQaSuite(params?: QaSuiteRunParams): Promise<QaSuiteResu
       gatewayProcessCpuStartMs,
       gatewayProcessCpuEndMs: gateway.getProcessCpuMs?.() ?? null,
       gatewayProcessRssStartBytes,
-      gatewayProcessRssEndBytes: gateway.getProcessRssBytes?.() ?? null,
+      gatewayProcessRssEndBytes: sampleGatewayProcessRss("suite-finish"),
+      gatewayProcessRssSamples,
     });
     const failedCount = scenarios.filter((scenario) => scenario.status === "fail").length;
     if (scenarios.some((scenario) => scenario.status === "fail")) {
@@ -1336,6 +1373,7 @@ export async function runQaSuite(params?: QaSuiteRunParams): Promise<QaSuiteResu
 }
 
 export const qaSuiteProgressTesting = {
+  buildQaSuiteRuntimeMetrics,
   buildQaRuntimeEnvPatch,
   parseQaSuiteBooleanEnv,
   remapModelRefForForcedRuntime,