diff --git a/package-lock.json b/package-lock.json
index 461a47b..1ea21d0 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -3979,7 +3979,6 @@
       "version": "1.1.0",
       "resolved": "https://registry.npmjs.org/@standard-schema/spec/-/spec-1.1.0.tgz",
       "integrity": "sha512-l2aFy5jALhniG5HgqrD6jXLi/rUWrKvqN/qJx6yoJsgKhblVd+iqqU4RCXavm/jPityDo5TCvKMnpjKnOriy0w==",
-      "dev": true,
       "license": "MIT"
     },
     "node_modules/@storybook/addon-a11y": {
@@ -7219,6 +7218,16 @@
       "integrity": "sha512-WMwm9LhRUo+WUaRN+vRuETqG89IgZphVSNkdFgeb6sS/E4OrDIN7t48CAewSHXc6C8lefD8KKfr5vY61brQlow==",
       "license": "MIT"
     },
+    "node_modules/effect": {
+      "version": "3.21.0",
+      "resolved": "https://registry.npmjs.org/effect/-/effect-3.21.0.tgz",
+      "integrity": "sha512-PPN80qRokCd1f015IANNhrwOnLO7GrrMQfk4/lnZRE/8j7UPWrNNjPV0uBrZutI/nHzernbW+J0hdqQysHiSnQ==",
+      "license": "MIT",
+      "dependencies": {
+        "@standard-schema/spec": "^1.0.0",
+        "fast-check": "^3.23.1"
+      }
+    },
     "node_modules/electron-to-chromium": {
       "version": "1.5.332",
       "resolved": "https://registry.npmjs.org/electron-to-chromium/-/electron-to-chromium-1.5.332.tgz",
@@ -8118,6 +8127,44 @@
       "integrity": "sha512-fjquC59cD7CyW6urNXK0FBufkZcoiGG80wTuPujX590cB5Ttln20E2UB4S/WARVqhXffZl2LNgS+gQdPIIim/g==",
       "license": "MIT"
     },
+    "node_modules/fast-check": {
+      "version": "3.23.2",
+      "resolved": "https://registry.npmjs.org/fast-check/-/fast-check-3.23.2.tgz",
+      "integrity": "sha512-h5+1OzzfCC3Ef7VbtKdcv7zsstUQwUDlYpUTvjeUsJAssPgLn7QzbboPtL5ro04Mq0rPOsMzl7q5hIbRs2wD1A==",
+      "funding": [
+        {
+          "type": "individual",
+          "url": "https://github.com/sponsors/dubzzz"
+        },
+        {
+          "type": "opencollective",
+          "url": "https://opencollective.com/fast-check"
+        }
+      ],
+      "license": "MIT",
+      "dependencies": {
+        "pure-rand": "^6.1.0"
+      },
+      "engines": {
+        "node": ">=8.0.0"
+      }
+    },
+    "node_modules/fast-check/node_modules/pure-rand": {
+      "version": "6.1.0",
+      "resolved": "https://registry.npmjs.org/pure-rand/-/pure-rand-6.1.0.tgz",
+      "integrity": "sha512-bVWawvoZoBYpp6yIoQtQXHZjmz35RSVHnUOTefl8Vcjr8snTPY1wnpSPMWekcFwbxI6gtmT7rSYPFvz71ldiOA==",
+      "funding": [
+        {
+          "type": "individual",
+          "url": "https://github.com/sponsors/dubzzz"
+        },
+        {
+          "type": "opencollective",
+          "url": "https://opencollective.com/fast-check"
+        }
+      ],
+      "license": "MIT"
+    },
     "node_modules/fast-deep-equal": {
       "version": "3.1.3",
       "resolved": "https://registry.npmjs.org/fast-deep-equal/-/fast-deep-equal-3.1.3.tgz",
@@ -15987,6 +16034,7 @@
         "better-sqlite3": "^12.8.0",
         "class-transformer": "^0.5.1",
         "class-validator": "^0.14.4",
+        "effect": "^3.21.0",
         "jsdom": "^29.0.2",
         "playwright": "^1.59.1",
         "reflect-metadata": "^0.2.2",
diff --git a/server/package.json b/server/package.json
index 9a2dbbc..2b3a616 100644
--- a/server/package.json
+++ b/server/package.json
@@ -32,6 +32,7 @@
     "better-sqlite3": "^12.8.0",
     "class-transformer": "^0.5.1",
     "class-validator": "^0.14.4",
+    "effect": "^3.21.0",
     "jsdom": "^29.0.2",
     "playwright": "^1.59.1",
     "reflect-metadata": "^0.2.2",
diff --git a/server/src/scenario/scenario-scheduler.service.ts b/server/src/scenario/scenario-scheduler.service.ts
index 4188c7f..e2e0513 100644
--- a/server/src/scenario/scenario-scheduler.service.ts
+++ b/server/src/scenario/scenario-scheduler.service.ts
@@ -2,6 +2,7 @@ import { Injectable, OnModuleInit } from "@nestjs/common";
 import { Interval } from "@nestjs/schedule";
 import { InjectRepository } from "@nestjs/typeorm";
 import * as crypto from "crypto";
+import { Effect } from "effect";
 import type { Browser, BrowserContext, Page } from "playwright";
 import { chromium } from "playwright";
 import { Repository } from "typeorm";
@@ -76,11 +77,29 @@ export class ScenarioSchedulerService implements OnModuleInit {
       this.logger.error(
         `Run #${run.id}: marked fail due to server restart (playwright session lost)`,
       );
-      await this.failRun(
-        run.id,
-        "Run aborted: server restarted and playwright session could not be recovered",
-      );
     }
+
+    await Effect.runPromise(
+      Effect.forEach(
+        staleRuns,
+        (run) =>
+          Effect.tryPromise(() =>
+            this.failRun(
+              run.id,
+              "Run aborted: server restarted and playwright session could not be recovered",
+            ),
+          ).pipe(
+            Effect.catchAll((err) =>
+              Effect.sync(() =>
+                this.logger.error(
+                  `Run #${run.id}: failRun threw unexpectedly — ${String(err)}`,
+                ),
+              ),
+            ),
+          ),
+        { concurrency: 10 },
+      ),
+    );
   }
 
   /**