diff --git a/examples/tests/sdk_tests/bucket/load_test.test.w b/examples/tests/sdk_tests/bucket/load_test.test.w
index 8231cb5da8c..0c4bd3a6545 100644
--- a/examples/tests/sdk_tests/bucket/load_test.test.w
+++ b/examples/tests/sdk_tests/bucket/load_test.test.w
@@ -2,8 +2,8 @@ bring cloud;
 
 let b = new cloud.Bucket();
 
-test "uploading many objects" {
+new std.Test(inflight () => {
   for i in 0..500 {
     b.put("test{i}", "{i}");
   }
-}
+}, timeout: 3m) as "uploading many objects";
diff --git a/libs/wingsdk/src/target-tf-gcp/bucket.ts b/libs/wingsdk/src/target-tf-gcp/bucket.ts
index a0d7f3e6968..23b6cd25134 100644
--- a/libs/wingsdk/src/target-tf-gcp/bucket.ts
+++ b/libs/wingsdk/src/target-tf-gcp/bucket.ts
@@ -1,7 +1,8 @@
+import { Fn } from "cdktf";
 import { Construct } from "constructs";
 import { App } from "./app";
 import { Function as GCPFunction } from "./function";
-import { calculateBucketPermissions } from "./permissions";
+import { createBucketPermissions } from "./permissions";
 import { ProjectService } from "../.gen/providers/google/project-service";
 import { StorageBucket } from "../.gen/providers/google/storage-bucket";
 import { StorageBucketIamMember } from "../.gen/providers/google/storage-bucket-iam-member";
@@ -197,8 +198,24 @@ export class Bucket extends cloud.Bucket {
       throw new Error("buckets can only be bound by tfgcp.Function for now");
     }
 
-    const permissions = calculateBucketPermissions(ops);
-    host.addPermissions(permissions);
+    if (ops.includes(cloud.BucketInflightMethods.SIGNED_URL)) {
+      host._addTokenCreator();
+    }
+
+    for (const role of createBucketPermissions(ops)) {
+      const bucketHash = Fn.sha256(this.bucket.name).slice(-8);
+      const permissionHash = Fn.sha256(role).slice(-8);
+
+      new StorageBucketIamMember(
+        this,
+        `bucket-iam-member-${bucketHash}-${permissionHash}`,
+        {
+          bucket: this.bucket.name,
+          role: role,
+          member: `serviceAccount:${host.serviceAccountEmail}`,
+        }
+      );
+    }
 
     host.addEnvironment(this.envName(), this.bucket.name);
     super.onLift(host, ops);
diff --git a/libs/wingsdk/src/target-tf-gcp/counter.ts b/libs/wingsdk/src/target-tf-gcp/counter.ts
index 2abd137632c..160bc296d62 100644
--- a/libs/wingsdk/src/target-tf-gcp/counter.ts
+++ b/libs/wingsdk/src/target-tf-gcp/counter.ts
@@ -72,8 +72,9 @@ export class Counter extends cloud.Counter {
       throw new Error("counters can only be bound by tfgcp.Function for now");
     }
 
-    const permissions = calculateCounterPermissions(ops);
-    host.addPermissions(permissions);
+    for (const role of calculateCounterPermissions(ops)) {
+      host._addProjectIamMember(role);
+    }
 
     host.addEnvironment(this.envName(), this.database.name);
     super.onLift(host, ops);
diff --git a/libs/wingsdk/src/target-tf-gcp/function.ts b/libs/wingsdk/src/target-tf-gcp/function.ts
index fd644a1f0de..93ce82b28df 100644
--- a/libs/wingsdk/src/target-tf-gcp/function.ts
+++ b/libs/wingsdk/src/target-tf-gcp/function.ts
@@ -7,9 +7,9 @@ import { Bucket } from "./bucket";
 import { core } from "..";
 import { CloudfunctionsFunction } from "../.gen/providers/google/cloudfunctions-function";
 import { CloudfunctionsFunctionIamMember } from "../.gen/providers/google/cloudfunctions-function-iam-member";
-import { ProjectIamCustomRole } from "../.gen/providers/google/project-iam-custom-role";
 import { ProjectIamMember } from "../.gen/providers/google/project-iam-member";
 import { ServiceAccount } from "../.gen/providers/google/service-account";
+import { ServiceAccountIamMember } from "../.gen/providers/google/service-account-iam-member";
 import { StorageBucketObject } from "../.gen/providers/google/storage-bucket-object";
 import * as cloud from "../cloud";
 import { LiftMap } from "../core";
@@ -73,11 +73,8 @@ export class Function extends cloud.Function {
   }
 
   private readonly function: CloudfunctionsFunction;
-  private readonly functionServiceAccount: ServiceAccount;
-  private readonly functionCustomRole: ProjectIamCustomRole;
-  private readonly permissions: Set<string> = new Set([
-    "cloudfunctions.functions.get",
-  ]);
+  public readonly functionServiceAccount: ServiceAccount;
+  private roles?: Set<string> = new Set();
 
   private assetPath: string | undefined; // posix path
 
@@ -136,7 +133,7 @@ export class Function extends cloud.Function {
       }
     );
 
-    // Step 1: Create Custom Service Account
+    // Create Custom Service Account
     this.functionServiceAccount = new ServiceAccount(
       this,
       `ServiceAccount${this.node.addr.substring(-8)}`,
@@ -147,25 +144,7 @@ export class Function extends cloud.Function {
         )}`,
       }
     );
-    // Step 2: Create Custom Role
-    this.functionCustomRole = new ProjectIamCustomRole(
-      this,
-      `CustomRole${this.node.addr.substring(-8)}`,
-      {
-        roleId: `cloudfunctions.custom${this.node.addr.substring(-8)}`,
-        title: `Custom Role for Cloud Function ${this.node.addr.substring(-8)}`,
-        permissions: Lazy.listValue({
-          produce: () => Array.from(this.permissions),
-        }),
-      }
-    );
-    // Step 3: Grant Custom Role to Custom Service Account on the Project
-    new ProjectIamMember(this, "ProjectIamMember", {
-      project: app.projectId,
-      role: `projects/${app.projectId}/roles/${this.functionCustomRole.roleId}`,
-      member: `serviceAccount:${this.functionServiceAccount.email}`,
-    });
-    // Step 4: Create the Cloud Function with Custom Service Account
+    // Create the Cloud Function with Custom Service Account
     this.function = new CloudfunctionsFunction(this, "DefaultFunction", {
       name: ResourceNames.generateName(this, FUNCTION_NAME_OPTS),
       description: "This function was created by Wing",
@@ -290,12 +269,6 @@ export class Function extends cloud.Function {
     );
   }
 
-  public addPermissions(permissions: string[]): void {
-    permissions.forEach((permission) => {
-      this.permissions.add(permission);
-    });
-  }
-
   public onLift(host: IInflightHost, ops: string[]): void {
     if (!(host instanceof Function)) {
       throw new Error(
@@ -304,7 +277,7 @@ export class Function extends cloud.Function {
     }
 
     if (ops.includes(cloud.FunctionInflightMethods.INVOKE)) {
-      host.addPermissions(["cloudfunctions.functions.invoke"]);
+      this._addPermissionToInvoke(host.serviceAccountEmail);
     }
 
     const { region, projectId } = App.of(this) as App;
@@ -320,16 +293,43 @@ export class Function extends cloud.Function {
    * @param serviceAccount The service account to grant invoke permissions to.
    * @internal
    */
-  public _addPermissionToInvoke(serviceAccount: ServiceAccount): void {
-    const hash = Fn.sha256(serviceAccount.email).slice(-8);
+  public _addPermissionToInvoke(serviceAccountEmail: string): void {
+    const hash = Fn.sha256(serviceAccountEmail).slice(-8);
 
     new CloudfunctionsFunctionIamMember(this, `invoker-permission-${hash}`, {
       project: this.function.project,
       region: this.function.region,
       cloudFunction: this.function.name,
       role: "roles/cloudfunctions.invoker",
-      member: `serviceAccount:${serviceAccount.email}`,
+      member: `serviceAccount:${serviceAccountEmail}`,
+    });
+  }
+
+  public _addTokenCreator() {
+    const tokenCreatorRole = "roles/iam.serviceAccountTokenCreator";
+    if (this.roles?.has(tokenCreatorRole)) {
+      return;
+    }
+    const hash = Fn.sha256(this.serviceAccountEmail).slice(-8);
+    new ServiceAccountIamMember(this, `service-iam-member-${hash}`, {
+      serviceAccountId: this.functionServiceAccount.name,
+      role: "roles/iam.serviceAccountTokenCreator",
+      member: `serviceAccount:${this.functionServiceAccount.email}`,
+    });
+    this.roles?.add(tokenCreatorRole);
+  }
+
+  public _addProjectIamMember(role: string) {
+    if (this.roles?.has(role)) {
+      return;
+    }
+    const hash = Fn.sha256(this.functionServiceAccount.email).slice(-8);
+    new ProjectIamMember(this, `project-iam-member-${hash}`, {
+      project: (App.of(this) as any).projectId,
+      member: `serviceAccount:${this.functionServiceAccount.email}`,
+      role,
     });
+    this.roles?.add(role);
   }
 
   /** @internal */
diff --git a/libs/wingsdk/src/target-tf-gcp/permissions.ts b/libs/wingsdk/src/target-tf-gcp/permissions.ts
index 3a5aa902a4e..b6589a2146a 100644
--- a/libs/wingsdk/src/target-tf-gcp/permissions.ts
+++ b/libs/wingsdk/src/target-tf-gcp/permissions.ts
@@ -1,59 +1,42 @@
 import * as cloud from "../cloud";
 
-export function calculateBucketPermissions(ops: string[]): string[] {
+export function createBucketPermissions(ops: string[]): string[] {
   const permissions: string[] = [];
 
-  if (
-    ops.includes(cloud.BucketInflightMethods.GET) ||
-    ops.includes(cloud.BucketInflightMethods.GET_JSON) ||
-    ops.includes(cloud.BucketInflightMethods.TRY_GET) ||
-    ops.includes(cloud.BucketInflightMethods.TRY_GET_JSON) ||
-    ops.includes(cloud.BucketInflightMethods.TRY_DELETE) ||
-    ops.includes(cloud.BucketInflightMethods.EXISTS) ||
-    ops.includes(cloud.BucketInflightMethods.METADATA) ||
-    ops.includes(cloud.BucketInflightMethods.PUBLIC_URL) ||
-    ops.includes(cloud.BucketInflightMethods.COPY) ||
-    ops.includes(cloud.BucketInflightMethods.RENAME) ||
-    ops.includes(cloud.BucketInflightMethods.SIGNED_URL)
-  ) {
-    permissions.push("storage.objects.get");
+  if (ops.includes(cloud.BucketInflightMethods.PUBLIC_URL)) {
+    permissions.push("roles/storage.insightsCollectorService");
   }
 
   if (
-    ops.includes(cloud.BucketInflightMethods.PUT) ||
-    ops.includes(cloud.BucketInflightMethods.PUT_JSON) ||
+    ops.includes(cloud.BucketInflightMethods.DELETE) ||
+    ops.includes(cloud.BucketInflightMethods.TRY_DELETE) ||
     ops.includes(cloud.BucketInflightMethods.COPY) ||
-    ops.includes(cloud.BucketInflightMethods.RENAME) ||
-    ops.includes(cloud.BucketInflightMethods.SIGNED_URL)
+    ops.includes(cloud.BucketInflightMethods.RENAME)
   ) {
-    permissions.push("storage.objects.create");
+    permissions.push("roles/storage.objectUser");
+    return permissions;
   }
 
   if (
-    ops.includes(cloud.BucketInflightMethods.DELETE) ||
-    ops.includes(cloud.BucketInflightMethods.TRY_DELETE) ||
     ops.includes(cloud.BucketInflightMethods.PUT) ||
     ops.includes(cloud.BucketInflightMethods.PUT_JSON) ||
-    ops.includes(cloud.BucketInflightMethods.COPY) ||
-    ops.includes(cloud.BucketInflightMethods.RENAME) ||
     ops.includes(cloud.BucketInflightMethods.SIGNED_URL)
   ) {
-    permissions.push("storage.objects.delete");
+    permissions.push("roles/storage.objectCreator");
   }
 
   if (
+    ops.includes(cloud.BucketInflightMethods.GET) ||
+    ops.includes(cloud.BucketInflightMethods.GET_JSON) ||
+    ops.includes(cloud.BucketInflightMethods.TRY_GET) ||
+    ops.includes(cloud.BucketInflightMethods.TRY_GET_JSON) ||
+    ops.includes(cloud.BucketInflightMethods.EXISTS) ||
+    ops.includes(cloud.BucketInflightMethods.METADATA) ||
+    ops.includes(cloud.BucketInflightMethods.PUBLIC_URL) ||
     ops.includes(cloud.BucketInflightMethods.LIST) ||
     ops.includes(cloud.BucketInflightMethods.SIGNED_URL)
   ) {
-    permissions.push("storage.objects.list");
-  }
-
-  if (ops.includes(cloud.BucketInflightMethods.PUBLIC_URL)) {
-    permissions.push("storage.buckets.get");
-  }
-
-  if (ops.includes(cloud.BucketInflightMethods.SIGNED_URL)) {
-    permissions.push("iam.serviceAccounts.signBlob");
+    permissions.push("roles/storage.objectViewer");
   }
 
   return permissions;
@@ -62,29 +45,13 @@ export function calculateBucketPermissions(ops: string[]): string[] {
 export function calculateCounterPermissions(ops: string[]): string[] {
   const permissions: string[] = [];
 
-  if (
-    ops.includes(cloud.CounterInflightMethods.PEEK) ||
-    ops.includes(cloud.CounterInflightMethods.INC) ||
-    ops.includes(cloud.CounterInflightMethods.DEC)
-  ) {
-    permissions.push("datastore.entities.get");
-  }
-
-  if (
-    ops.includes(cloud.CounterInflightMethods.PEEK) ||
-    ops.includes(cloud.CounterInflightMethods.INC) ||
-    ops.includes(cloud.CounterInflightMethods.DEC) ||
-    ops.includes(cloud.CounterInflightMethods.SET)
-  ) {
-    permissions.push("datastore.entities.create");
-  }
-
   if (
     ops.includes(cloud.CounterInflightMethods.INC) ||
     ops.includes(cloud.CounterInflightMethods.DEC) ||
-    ops.includes(cloud.CounterInflightMethods.SET)
+    ops.includes(cloud.CounterInflightMethods.SET) ||
+    ops.includes(cloud.CounterInflightMethods.PEEK)
   ) {
-    permissions.push("datastore.entities.update");
+    permissions.push("roles/datastore.user");
   }
 
   return permissions;
diff --git a/libs/wingsdk/src/target-tf-gcp/schedule.ts b/libs/wingsdk/src/target-tf-gcp/schedule.ts
index 7a9609605de..d2bb294e636 100644
--- a/libs/wingsdk/src/target-tf-gcp/schedule.ts
+++ b/libs/wingsdk/src/target-tf-gcp/schedule.ts
@@ -66,7 +66,7 @@ export class Schedule extends cloud.Schedule {
     );
 
     // allow scheduler service account to invoke cron function
-    cronFunction._addPermissionToInvoke(schedulerServiceAccount);
+    cronFunction._addPermissionToInvoke(schedulerServiceAccount.email);
 
     // create scheduler
     new CloudSchedulerJob(this, "Scheduler", {