diff --git a/backend/src/ee/services/access-approval-request/access-approval-request-service.ts b/backend/src/ee/services/access-approval-request/access-approval-request-service.ts
index da87978fd3..d69c6da790 100644
--- a/backend/src/ee/services/access-approval-request/access-approval-request-service.ts
+++ b/backend/src/ee/services/access-approval-request/access-approval-request-service.ts
@@ -35,7 +35,7 @@ import { ApprovalStatus, TAccessApprovalRequestServiceFactory } from "./access-a
 
 type TSecretApprovalRequestServiceFactoryDep = {
   additionalPrivilegeDAL: Pick<TProjectUserAdditionalPrivilegeDALFactory, "create" | "findById">;
-  permissionService: Pick<TPermissionServiceFactory, "getProjectPermission">;
+  permissionService: Pick<TPermissionServiceFactory, "getProjectPermission" | "invalidateProjectPermissionCache">;
   accessApprovalPolicyApproverDAL: Pick<TAccessApprovalPolicyApproverDALFactory, "find">;
   projectEnvDAL: Pick<TProjectEnvDALFactory, "findOne">;
   projectDAL: Pick<
@@ -758,6 +758,8 @@ export const accessApprovalRequestServiceFactory = ({
             { privilegeId: privilegeIdToSet, status: ApprovalStatus.APPROVED },
             tx
           );
+
+          await permissionService.invalidateProjectPermissionCache(accessApprovalRequest.projectId, tx);
         }
       }
 
diff --git a/backend/src/ee/services/group/group-service.ts b/backend/src/ee/services/group/group-service.ts
index 46c9831b08..d4d30b5ae9 100644
--- a/backend/src/ee/services/group/group-service.ts
+++ b/backend/src/ee/services/group/group-service.ts
@@ -44,7 +44,10 @@ type TGroupServiceFactoryDep = {
   projectDAL: Pick<TProjectDALFactory, "findProjectGhostUser" | "findById">;
   projectBotDAL: Pick<TProjectBotDALFactory, "findOne">;
   projectKeyDAL: Pick<TProjectKeyDALFactory, "find" | "delete" | "findLatestProjectKey" | "insertMany">;
-  permissionService: Pick<TPermissionServiceFactory, "getOrgPermission" | "getOrgPermissionByRole">;
+  permissionService: Pick<
+    TPermissionServiceFactory,
+    "getOrgPermission" | "getOrgPermissionByRole" | "invalidateProjectPermissionCache"
+  >;
   licenseService: Pick<TLicenseServiceFactory, "getPlan">;
   oidcConfigDAL: Pick<TOidcConfigDALFactory, "findOne">;
 };
@@ -225,6 +228,15 @@ export const groupServiceFactory = ({
       return updated;
     });
 
+    if (role) {
+      const groupProjects = await groupProjectDAL.find({ groupId: group.id });
+      await Promise.allSettled([
+        ...groupProjects.map((groupProject) =>
+          permissionService.invalidateProjectPermissionCache(groupProject.projectId)
+        )
+      ]);
+    }
+
     return updatedGroup;
   };
 
@@ -247,11 +259,17 @@ export const groupServiceFactory = ({
         message: "Failed to delete group due to plan restriction. Upgrade plan to delete group."
       });
 
+    const groupProjects = await groupProjectDAL.find({ groupId: id });
+
     const [group] = await groupDAL.delete({
       id,
       orgId: actorOrgId
     });
 
+    await Promise.allSettled([
+      ...groupProjects.map((groupProject) => permissionService.invalidateProjectPermissionCache(groupProject.projectId))
+    ]);
+
     return group;
   };
 
@@ -398,6 +416,11 @@ export const groupServiceFactory = ({
       projectBotDAL
     });
 
+    const groupProjects = await groupProjectDAL.find({ groupId: group.id });
+    await Promise.allSettled([
+      ...groupProjects.map((groupProject) => permissionService.invalidateProjectPermissionCache(groupProject.projectId))
+    ]);
+
     return users[0];
   };
 
@@ -479,6 +502,11 @@ export const groupServiceFactory = ({
       projectKeyDAL
     });
 
+    const groupProjects = await groupProjectDAL.find({ groupId: group.id });
+    await Promise.allSettled([
+      ...groupProjects.map((groupProject) => permissionService.invalidateProjectPermissionCache(groupProject.projectId))
+    ]);
+
     return users[0];
   };
 
diff --git a/backend/src/ee/services/identity-project-additional-privilege-v2/identity-project-additional-privilege-v2-service.ts b/backend/src/ee/services/identity-project-additional-privilege-v2/identity-project-additional-privilege-v2-service.ts
index 64da588f8d..27b67367e0 100644
--- a/backend/src/ee/services/identity-project-additional-privilege-v2/identity-project-additional-privilege-v2-service.ts
+++ b/backend/src/ee/services/identity-project-additional-privilege-v2/identity-project-additional-privilege-v2-service.ts
@@ -28,7 +28,7 @@ type TIdentityProjectAdditionalPrivilegeV2ServiceFactoryDep = {
   identityProjectAdditionalPrivilegeDAL: TIdentityProjectAdditionalPrivilegeV2DALFactory;
   identityProjectDAL: Pick<TIdentityProjectDALFactory, "findOne" | "findById">;
   projectDAL: Pick<TProjectDALFactory, "findProjectBySlug">;
-  permissionService: Pick<TPermissionServiceFactory, "getProjectPermission">;
+  permissionService: Pick<TPermissionServiceFactory, "getProjectPermission" | "invalidateProjectPermissionCache">;
 };
 
 export type TIdentityProjectAdditionalPrivilegeV2ServiceFactory = ReturnType<
@@ -115,6 +115,8 @@ export const identityProjectAdditionalPrivilegeV2ServiceFactory = ({
         permissions: packedPermission
       });
 
+      await permissionService.invalidateProjectPermissionCache(identityProjectMembership.projectId);
+
       return {
         ...additionalPrivilege,
         permissions: unpackPermissions(additionalPrivilege.permissions)
@@ -132,6 +134,9 @@ export const identityProjectAdditionalPrivilegeV2ServiceFactory = ({
       temporaryAccessStartTime: new Date(dto.temporaryAccessStartTime),
       temporaryAccessEndTime: new Date(new Date(dto.temporaryAccessStartTime).getTime() + relativeTempAllocatedTimeInMs)
     });
+
+    await permissionService.invalidateProjectPermissionCache(identityProjectMembership.projectId);
+
     return {
       ...additionalPrivilege,
       permissions: unpackPermissions(additionalPrivilege.permissions)
@@ -224,6 +229,9 @@ export const identityProjectAdditionalPrivilegeV2ServiceFactory = ({
         temporaryAccessStartTime: new Date(temporaryAccessStartTime || ""),
         temporaryAccessEndTime: new Date(new Date(temporaryAccessStartTime || "").getTime() + ms(temporaryRange || ""))
       });
+
+      await permissionService.invalidateProjectPermissionCache(identityProjectMembership.projectId);
+
       return {
         ...additionalPrivilege,
         permissions: unpackPermissions(additionalPrivilege.permissions)
@@ -239,6 +247,9 @@ export const identityProjectAdditionalPrivilegeV2ServiceFactory = ({
       temporaryRange: null,
       temporaryMode: null
     });
+
+    await permissionService.invalidateProjectPermissionCache(identityProjectMembership.projectId);
+
     return {
       ...additionalPrivilege,
       permissions: unpackPermissions(additionalPrivilege.permissions)
@@ -294,6 +305,9 @@ export const identityProjectAdditionalPrivilegeV2ServiceFactory = ({
       });
 
     const deletedPrivilege = await identityProjectAdditionalPrivilegeDAL.deleteById(identityPrivilege.id);
+
+    await permissionService.invalidateProjectPermissionCache(identityProjectMembership.projectId);
+
     return {
       ...deletedPrivilege,
       permissions: unpackPermissions(deletedPrivilege.permissions)
diff --git a/backend/src/ee/services/identity-project-additional-privilege/identity-project-additional-privilege-service.ts b/backend/src/ee/services/identity-project-additional-privilege/identity-project-additional-privilege-service.ts
index 828cf43a37..ddba76920a 100644
--- a/backend/src/ee/services/identity-project-additional-privilege/identity-project-additional-privilege-service.ts
+++ b/backend/src/ee/services/identity-project-additional-privilege/identity-project-additional-privilege-service.ts
@@ -31,7 +31,7 @@ type TIdentityProjectAdditionalPrivilegeServiceFactoryDep = {
   identityProjectAdditionalPrivilegeDAL: TIdentityProjectAdditionalPrivilegeDALFactory;
   identityProjectDAL: Pick<TIdentityProjectDALFactory, "findOne" | "findById">;
   projectDAL: Pick<TProjectDALFactory, "findProjectBySlug">;
-  permissionService: Pick<TPermissionServiceFactory, "getProjectPermission">;
+  permissionService: Pick<TPermissionServiceFactory, "getProjectPermission" | "invalidateProjectPermissionCache">;
 };
 
 export type TIdentityProjectAdditionalPrivilegeServiceFactory = ReturnType<
@@ -129,6 +129,9 @@ export const identityProjectAdditionalPrivilegeServiceFactory = ({
         slug,
         permissions: packedPermission
       });
+
+      await permissionService.invalidateProjectPermissionCache(identityProjectMembership.projectId);
+
       return {
         ...additionalPrivilege,
         permissions: unpackPermissions(additionalPrivilege.permissions)
@@ -146,6 +149,9 @@ export const identityProjectAdditionalPrivilegeServiceFactory = ({
       temporaryAccessStartTime: new Date(dto.temporaryAccessStartTime),
       temporaryAccessEndTime: new Date(new Date(dto.temporaryAccessStartTime).getTime() + relativeTempAllocatedTimeInMs)
     });
+
+    await permissionService.invalidateProjectPermissionCache(identityProjectMembership.projectId);
+
     return {
       ...additionalPrivilege,
       permissions: unpackPermissions(additionalPrivilege.permissions)
@@ -250,6 +256,9 @@ export const identityProjectAdditionalPrivilegeServiceFactory = ({
         temporaryAccessStartTime: new Date(temporaryAccessStartTime || ""),
         temporaryAccessEndTime: new Date(new Date(temporaryAccessStartTime || "").getTime() + ms(temporaryRange || ""))
       });
+
+      await permissionService.invalidateProjectPermissionCache(identityProjectMembership.projectId);
+
       return {
         ...additionalPrivilege,
         permissions: unpackPermissions(additionalPrivilege.permissions)
@@ -265,6 +274,9 @@ export const identityProjectAdditionalPrivilegeServiceFactory = ({
       temporaryRange: null,
       temporaryMode: null
     });
+
+    await permissionService.invalidateProjectPermissionCache(identityProjectMembership.projectId);
+
     return {
       ...additionalPrivilege,
       permissions: unpackPermissions(additionalPrivilege.permissions)
@@ -338,9 +350,11 @@ export const identityProjectAdditionalPrivilegeServiceFactory = ({
     }
 
     const deletedPrivilege = await identityProjectAdditionalPrivilegeDAL.deleteById(identityPrivilege.id);
+
+    await permissionService.invalidateProjectPermissionCache(identityProjectMembership.projectId);
+
     return {
       ...deletedPrivilege,
-
       permissions: unpackPermissions(deletedPrivilege.permissions)
     };
   };
diff --git a/backend/src/ee/services/permission/permission-service-types.ts b/backend/src/ee/services/permission/permission-service-types.ts
index 5e71c65d94..f25b84bd59 100644
--- a/backend/src/ee/services/permission/permission-service-types.ts
+++ b/backend/src/ee/services/permission/permission-service-types.ts
@@ -1,5 +1,6 @@
 import { MongoAbility, RawRuleOf } from "@casl/ability";
 import { MongoQuery } from "@ucast/mongo2js";
+import { Knex } from "knex";
 
 import { ActionProjectType } from "@app/db/schemas";
 import { ActorAuthMethod, ActorType } from "@app/services/auth/auth-type";
@@ -283,4 +284,5 @@ export type TPermissionServiceFactory = {
     projectId: string;
     checkPermissions: ProjectPermissionSet;
   }) => Promise<boolean>;
+  invalidateProjectPermissionCache: (projectId: string, tx?: Knex) => Promise<void>;
 };
diff --git a/backend/src/ee/services/permission/permission-service.ts b/backend/src/ee/services/permission/permission-service.ts
index 461ceef461..9e94e14158 100644
--- a/backend/src/ee/services/permission/permission-service.ts
+++ b/backend/src/ee/services/permission/permission-service.ts
@@ -3,6 +3,7 @@ import { PackRule, unpackRules } from "@casl/ability/extra";
 import { requestContext } from "@fastify/request-context";
 import { MongoQuery } from "@ucast/mongo2js";
 import handlebars from "handlebars";
+import { Knex } from "knex";
 
 import {
   ActionProjectType,
@@ -20,9 +21,11 @@ import {
   projectViewerPermission,
   sshHostBootstrapPermissions
 } from "@app/ee/services/permission/default-roles";
+import { KeyStorePrefixes, KeyStoreTtls, TKeyStoreFactory } from "@app/keystore/keystore";
 import { conditionsMatcher } from "@app/lib/casl";
 import { BadRequestError, ForbiddenRequestError, NotFoundError } from "@app/lib/errors";
 import { objectify } from "@app/lib/fn";
+import { logger } from "@app/lib/logger";
 import { ActorType } from "@app/services/auth/auth-type";
 import { TOrgRoleDALFactory } from "@app/services/org/org-role-dal";
 import { TProjectDALFactory } from "@app/services/project/project-dal";
@@ -49,6 +52,7 @@ type TPermissionServiceFactoryDep = {
   serviceTokenDAL: Pick<TServiceTokenDALFactory, "findById">;
   projectDAL: Pick<TProjectDALFactory, "findById">;
   permissionDAL: TPermissionDALFactory;
+  keyStore: TKeyStoreFactory;
 };
 
 export const permissionServiceFactory = ({
@@ -56,7 +60,8 @@ export const permissionServiceFactory = ({
   orgRoleDAL,
   projectRoleDAL,
   serviceTokenDAL,
-  projectDAL
+  projectDAL,
+  keyStore
 }: TPermissionServiceFactoryDep): TPermissionServiceFactory => {
   const buildOrgPermission = (orgUserRoles: TBuildOrgPermissionDTO) => {
     const rules = orgUserRoles
@@ -83,6 +88,68 @@ export const permissionServiceFactory = ({
     });
   };
 
+  const invalidateProjectPermissionCache = async (projectId: string, tx?: Knex) => {
+    const projectPermissionDalVersionKey = KeyStorePrefixes.ProjectPermissionDalVersion(projectId);
+    await keyStore.pgIncrementBy(projectPermissionDalVersionKey, {
+      incr: 1,
+      tx,
+      expiry: KeyStoreTtls.ProjectPermissionDalVersionTtl
+    });
+  };
+
+  const calculateProjectPermissionTtl = (membership: unknown): number => {
+    const now = new Date();
+    let minTtl = KeyStoreTtls.ProjectPermissionCacheInSeconds;
+
+    const getMinEndTime = (items: Array<{ temporaryAccessEndTime?: Date | null; isTemporary?: boolean }>) => {
+      return items
+        .filter((item) => item.isTemporary && item.temporaryAccessEndTime)
+        .map((item) => item.temporaryAccessEndTime!)
+        .filter((endTime) => endTime > now)
+        .reduce((min, endTime) => (!min || endTime < min ? endTime : min), null as Date | null);
+    };
+
+    const roleTimes: Date[] = [];
+    const additionalPrivilegeTimes: Date[] = [];
+
+    if (
+      membership &&
+      typeof membership === "object" &&
+      "roles" in membership &&
+      Array.isArray((membership as Record<string, unknown>).roles)
+    ) {
+      const roles = (membership as Record<string, unknown>).roles as Array<{
+        temporaryAccessEndTime?: Date | null;
+        isTemporary?: boolean;
+      }>;
+      const minRoleEndTime = getMinEndTime(roles);
+      if (minRoleEndTime) roleTimes.push(minRoleEndTime);
+    }
+
+    if (
+      membership &&
+      typeof membership === "object" &&
+      "additionalPrivileges" in membership &&
+      Array.isArray((membership as Record<string, unknown>).additionalPrivileges)
+    ) {
+      const additionalPrivileges = (membership as Record<string, unknown>).additionalPrivileges as Array<{
+        temporaryAccessEndTime?: Date | null;
+        isTemporary?: boolean;
+      }>;
+      const minAdditionalEndTime = getMinEndTime(additionalPrivileges);
+      if (minAdditionalEndTime) additionalPrivilegeTimes.push(minAdditionalEndTime);
+    }
+
+    const allEndTimes = [...roleTimes, ...additionalPrivilegeTimes];
+    if (allEndTimes.length > 0) {
+      const nearestEndTime = allEndTimes.reduce((min, endTime) => (!min || endTime < min ? endTime : min));
+      const timeUntilExpiry = Math.floor((nearestEndTime.getTime() - now.getTime()) / 1000);
+      minTtl = Math.min(minTtl, Math.max(1, timeUntilExpiry));
+    }
+
+    return minTtl;
+  };
+
   const buildProjectPermissionRules = (projectUserRoles: TBuildProjectPermissionDTO) => {
     const rules = projectUserRoles
       .map(({ role, permissions }) => {
@@ -577,35 +644,94 @@ export const permissionServiceFactory = ({
       actorId = assumedPrivilegeDetailsCtx.actorId;
     }
 
+    if (actor === ActorType.SERVICE) {
+      return getServiceTokenProjectPermission({
+        serviceTokenId: actorId,
+        projectId,
+        actorOrgId,
+        actionProjectType
+      }) as Promise<TProjectPermissionRT<T>>;
+    }
+
+    const cachedProjectPermissionVersion = await keyStore.pgGetIntItem(
+      KeyStorePrefixes.ProjectPermissionDalVersion(projectId)
+    );
+    const projectPermissionVersion = Number(cachedProjectPermissionVersion || 0);
+    const cacheKey = KeyStorePrefixes.ProjectPermission(
+      projectId,
+      projectPermissionVersion,
+      actor,
+      actorId,
+      actionProjectType || ActionProjectType.Any
+    );
+
+    try {
+      const cachedData = await keyStore.getItem(cacheKey);
+      if (cachedData) {
+        const parsed = JSON.parse(cachedData) as {
+          rules: RawRuleOf<MongoAbility<ProjectPermissionSet>>[];
+          membership: {
+            roles?: Array<{ role: string; customRoleSlug?: string }>;
+            [key: string]: unknown;
+          };
+        };
+        const permission = createMongoAbility<ProjectPermissionSet>(parsed.rules, {
+          conditionsMatcher
+        });
+
+        return {
+          permission,
+          membership: parsed.membership,
+          hasRole: (role: string) =>
+            parsed.membership.roles?.findIndex(
+              ({ role: slug, customRoleSlug }) => role === slug || slug === customRoleSlug
+            ) !== -1
+        } as TProjectPermissionRT<T>;
+      }
+    } catch (error) {
+      logger.error(error, "Failed to get project permission");
+    }
+
+    let result: TProjectPermissionRT<T>;
+
     switch (actor) {
       case ActorType.USER:
-        return getUserProjectPermission({
+        result = (await getUserProjectPermission({
           userId: actorId,
           projectId,
           authMethod: actorAuthMethod,
           userOrgId: actorOrgId,
           actionProjectType
-        }) as Promise<TProjectPermissionRT<T>>;
-      case ActorType.SERVICE:
-        return getServiceTokenProjectPermission({
-          serviceTokenId: actorId,
-          projectId,
-          actorOrgId,
-          actionProjectType
-        }) as Promise<TProjectPermissionRT<T>>;
+        })) as TProjectPermissionRT<T>;
+        break;
       case ActorType.IDENTITY:
-        return getIdentityProjectPermission({
+        result = (await getIdentityProjectPermission({
           identityId: actorId,
           projectId,
           identityOrgId: actorOrgId,
           actionProjectType
-        }) as Promise<TProjectPermissionRT<T>>;
+        })) as TProjectPermissionRT<T>;
+        break;
       default:
         throw new BadRequestError({
           message: "Invalid actor provided",
           name: "Get project permission"
         });
     }
+
+    try {
+      const cacheData = {
+        rules: result.permission.rules,
+        membership: result.membership
+      };
+
+      const ttl = calculateProjectPermissionTtl(result.membership);
+      await keyStore.setItemWithExpiry(cacheKey, ttl, JSON.stringify(cacheData));
+    } catch (error) {
+      logger.error(error, "Failed to cache project permission");
+    }
+
+    return result;
   };
 
   const getProjectPermissionByRole: TPermissionServiceFactory["getProjectPermissionByRole"] = async (
@@ -668,6 +794,7 @@ export const permissionServiceFactory = ({
     getProjectPermissionByRole,
     buildOrgPermission,
     buildProjectPermissionRules,
-    checkGroupProjectPermission
+    checkGroupProjectPermission,
+    invalidateProjectPermissionCache
   };
 };
diff --git a/backend/src/ee/services/project-user-additional-privilege/project-user-additional-privilege-service.ts b/backend/src/ee/services/project-user-additional-privilege/project-user-additional-privilege-service.ts
index 944775156e..c2876572f1 100644
--- a/backend/src/ee/services/project-user-additional-privilege/project-user-additional-privilege-service.ts
+++ b/backend/src/ee/services/project-user-additional-privilege/project-user-additional-privilege-service.ts
@@ -27,7 +27,7 @@ import {
 type TProjectUserAdditionalPrivilegeServiceFactoryDep = {
   projectUserAdditionalPrivilegeDAL: TProjectUserAdditionalPrivilegeDALFactory;
   projectMembershipDAL: Pick<TProjectMembershipDALFactory, "findById" | "findOne">;
-  permissionService: Pick<TPermissionServiceFactory, "getProjectPermission">;
+  permissionService: Pick<TPermissionServiceFactory, "getProjectPermission" | "invalidateProjectPermissionCache">;
   accessApprovalRequestDAL: Pick<TAccessApprovalRequestDALFactory, "update">;
 };
 
@@ -115,6 +115,9 @@ export const projectUserAdditionalPrivilegeServiceFactory = ({
         slug,
         permissions: packedPermission
       });
+
+      await permissionService.invalidateProjectPermissionCache(projectMembership.projectId);
+
       return {
         ...additionalPrivilege,
         permissions: unpackPermissions(additionalPrivilege.permissions)
@@ -133,6 +136,9 @@ export const projectUserAdditionalPrivilegeServiceFactory = ({
       temporaryAccessStartTime: new Date(dto.temporaryAccessStartTime),
       temporaryAccessEndTime: new Date(new Date(dto.temporaryAccessStartTime).getTime() + relativeTempAllocatedTimeInMs)
     });
+
+    await permissionService.invalidateProjectPermissionCache(projectMembership.projectId);
+
     return {
       ...additionalPrivilege,
       permissions: unpackPermissions(additionalPrivilege.permissions)
@@ -230,6 +236,8 @@ export const projectUserAdditionalPrivilegeServiceFactory = ({
         temporaryAccessEndTime: new Date(new Date(temporaryAccessStartTime || "").getTime() + ms(temporaryRange || ""))
       });
 
+      await permissionService.invalidateProjectPermissionCache(projectMembership.projectId);
+
       return {
         ...additionalPrivilege,
         permissions: unpackPermissions(additionalPrivilege.permissions)
@@ -245,6 +253,9 @@ export const projectUserAdditionalPrivilegeServiceFactory = ({
       temporaryRange: null,
       temporaryMode: null
     });
+
+    await permissionService.invalidateProjectPermissionCache(projectMembership.projectId);
+
     return {
       ...additionalPrivilege,
       permissions: unpackPermissions(additionalPrivilege.permissions)
@@ -291,6 +302,9 @@ export const projectUserAdditionalPrivilegeServiceFactory = ({
       }
     );
     const deletedPrivilege = await projectUserAdditionalPrivilegeDAL.deleteById(userPrivilege.id);
+
+    await permissionService.invalidateProjectPermissionCache(projectMembership.projectId);
+
     return {
       ...deletedPrivilege,
       permissions: unpackPermissions(deletedPrivilege.permissions)
diff --git a/backend/src/keystore/keystore.ts b/backend/src/keystore/keystore.ts
index 04ba8428b5..17f4aa4937 100644
--- a/backend/src/keystore/keystore.ts
+++ b/backend/src/keystore/keystore.ts
@@ -63,13 +63,28 @@ export const KeyStorePrefixes = {
   ActiveSSEConnectionsSet: (projectId: string, identityId: string) =>
     `sse-connections:${projectId}:${identityId}` as const,
   ActiveSSEConnections: (projectId: string, identityId: string, connectionId: string) =>
-    `sse-connections:${projectId}:${identityId}:${connectionId}` as const
+    `sse-connections:${projectId}:${identityId}:${connectionId}` as const,
+
+  ProjectPermission: (
+    projectId: string,
+    version: number,
+    actorType: string,
+    actorId: string,
+    actionProjectType: string
+  ) => `project-permission:${projectId}:${version}:${actorType}:${actorId}:${actionProjectType}` as const,
+  ProjectPermissionDalVersion: (projectId: string) => `project-permission:${projectId}:dal-version` as const,
+  UserProjectPermissionPattern: (userId: string) => `project-permission:*:*:USER:${userId}:*` as const,
+  IdentityProjectPermissionPattern: (identityId: string) => `project-permission:*:*:IDENTITY:${identityId}:*` as const,
+  GroupMemberProjectPermissionPattern: (projectId: string, groupId: string) =>
+    `group-member-project-permission:${projectId}:${groupId}:*` as const
 };
 
 export const KeyStoreTtls = {
   SetSyncSecretIntegrationLastRunTimestampInSeconds: 60,
   SetSecretSyncLastRunTimestampInSeconds: 60,
-  AccessTokenStatusUpdateInSeconds: 120
+  AccessTokenStatusUpdateInSeconds: 120,
+  ProjectPermissionCacheInSeconds: 300, // 5 minutes
+  ProjectPermissionDalVersionTtl: "15m" // Project permission DAL version TTL
 };
 
 type TDeleteItems = {
diff --git a/backend/src/server/routes/index.ts b/backend/src/server/routes/index.ts
index 2fb7e9ff72..3171919a96 100644
--- a/backend/src/server/routes/index.ts
+++ b/backend/src/server/routes/index.ts
@@ -530,7 +530,8 @@ export const registerRoutes = async (
     orgRoleDAL,
     projectRoleDAL,
     serviceTokenDAL,
-    projectDAL
+    projectDAL,
+    keyStore
   });
   const assumePrivilegeService = assumePrivilegeServiceFactory({
     projectDAL,
diff --git a/backend/src/services/group-project/group-project-service.ts b/backend/src/services/group-project/group-project-service.ts
index 838d894375..913aca2f34 100644
--- a/backend/src/services/group-project/group-project-service.ts
+++ b/backend/src/services/group-project/group-project-service.ts
@@ -37,13 +37,16 @@ type TGroupProjectServiceFactoryDep = {
     TGroupProjectMembershipRoleDALFactory,
     "create" | "transaction" | "insertMany" | "delete"
   >;
-  userGroupMembershipDAL: Pick<TUserGroupMembershipDALFactory, "findGroupMembersNotInProject">;
+  userGroupMembershipDAL: Pick<TUserGroupMembershipDALFactory, "findGroupMembersNotInProject" | "find">;
   projectDAL: Pick<TProjectDALFactory, "findOne" | "findProjectGhostUser" | "findById">;
   projectKeyDAL: Pick<TProjectKeyDALFactory, "findLatestProjectKey" | "delete" | "insertMany" | "transaction">;
   projectRoleDAL: Pick<TProjectRoleDALFactory, "find">;
   projectBotDAL: TProjectBotDALFactory;
   groupDAL: Pick<TGroupDALFactory, "findOne" | "findAllGroupPossibleMembers">;
-  permissionService: Pick<TPermissionServiceFactory, "getProjectPermission" | "getProjectPermissionByRole">;
+  permissionService: Pick<
+    TPermissionServiceFactory,
+    "getProjectPermission" | "getProjectPermissionByRole" | "invalidateProjectPermissionCache"
+  >;
 };
 
 export type TGroupProjectServiceFactory = ReturnType<typeof groupProjectServiceFactory>;
@@ -263,6 +266,8 @@ export const groupProjectServiceFactory = ({
       return groupProjectMembership;
     });
 
+    await permissionService.invalidateProjectPermissionCache(projectId);
+
     return projectGroup;
   };
 
@@ -372,6 +377,8 @@ export const groupProjectServiceFactory = ({
       return groupProjectMembershipRoleDAL.insertMany(sanitizedProjectMembershipRoles, tx);
     });
 
+    await permissionService.invalidateProjectPermissionCache(projectId);
+
     return updatedRoles;
   };
 
@@ -404,14 +411,18 @@ export const groupProjectServiceFactory = ({
     ForbiddenError.from(permission).throwUnlessCan(ProjectPermissionGroupActions.Delete, ProjectPermissionSub.Groups);
 
     const deletedProjectGroup = await groupProjectDAL.transaction(async (tx) => {
-      const groupMembers = await userGroupMembershipDAL.findGroupMembersNotInProject(group.id, project.id, tx);
+      const groupMembersNotInProject = await userGroupMembershipDAL.findGroupMembersNotInProject(
+        group.id,
+        project.id,
+        tx
+      );
 
-      if (groupMembers.length) {
+      if (groupMembersNotInProject.length) {
         await projectKeyDAL.delete(
           {
             projectId: project.id,
             $in: {
-              receiverId: groupMembers.map(({ user: { id } }) => id)
+              receiverId: groupMembersNotInProject.map(({ user: { id } }) => id)
             }
           },
           tx
@@ -422,6 +433,8 @@ export const groupProjectServiceFactory = ({
       return projectGroup;
     });
 
+    await permissionService.invalidateProjectPermissionCache(projectId);
+
     return deletedProjectGroup;
   };
 
diff --git a/backend/src/services/identity-project/identity-project-service.ts b/backend/src/services/identity-project/identity-project-service.ts
index 4f0964f42d..08fd2cf0be 100644
--- a/backend/src/services/identity-project/identity-project-service.ts
+++ b/backend/src/services/identity-project/identity-project-service.ts
@@ -35,7 +35,10 @@ type TIdentityProjectServiceFactoryDep = {
   projectDAL: Pick<TProjectDALFactory, "findById">;
   projectRoleDAL: Pick<TProjectRoleDALFactory, "find">;
   identityOrgMembershipDAL: Pick<TIdentityOrgDALFactory, "findOne">;
-  permissionService: Pick<TPermissionServiceFactory, "getProjectPermission" | "getProjectPermissionByRole">;
+  permissionService: Pick<
+    TPermissionServiceFactory,
+    "getProjectPermission" | "getProjectPermissionByRole" | "invalidateProjectPermissionCache"
+  >;
 };
 
 export type TIdentityProjectServiceFactory = ReturnType<typeof identityProjectServiceFactory>;
@@ -165,6 +168,9 @@ export const identityProjectServiceFactory = ({
       const identityRoles = await identityProjectMembershipRoleDAL.insertMany(sanitizedProjectMembershipRoles, tx);
       return { ...identityProjectMembership, roles: identityRoles };
     });
+
+    await permissionService.invalidateProjectPermissionCache(projectId);
+
     return projectIdentity;
   };
 
@@ -272,6 +278,8 @@ export const identityProjectServiceFactory = ({
       return identityProjectMembershipRoleDAL.insertMany(sanitizedProjectMembershipRoles, tx);
     });
 
+    await permissionService.invalidateProjectPermissionCache(projectId);
+
     return updatedRoles;
   };
 
@@ -302,6 +310,9 @@ export const identityProjectServiceFactory = ({
     );
 
     const [deletedIdentity] = await identityProjectDAL.delete({ identityId, projectId });
+
+    await permissionService.invalidateProjectPermissionCache(projectId);
+
     return deletedIdentity;
   };
 
diff --git a/backend/src/services/project-membership/project-membership-service.ts b/backend/src/services/project-membership/project-membership-service.ts
index 991bf65d16..301ce1bc04 100644
--- a/backend/src/services/project-membership/project-membership-service.ts
+++ b/backend/src/services/project-membership/project-membership-service.ts
@@ -43,7 +43,10 @@ import {
 import { TProjectUserMembershipRoleDALFactory } from "./project-user-membership-role-dal";
 
 type TProjectMembershipServiceFactoryDep = {
-  permissionService: Pick<TPermissionServiceFactory, "getProjectPermission" | "getProjectPermissionByRole">;
+  permissionService: Pick<
+    TPermissionServiceFactory,
+    "getProjectPermission" | "getProjectPermissionByRole" | "invalidateProjectPermissionCache"
+  >;
   smtpService: TSmtpService;
   projectBotDAL: TProjectBotDALFactory;
   projectMembershipDAL: TProjectMembershipDALFactory;
@@ -239,6 +242,8 @@ export const projectMembershipServiceFactory = ({
       );
     });
 
+    await permissionService.invalidateProjectPermissionCache(projectId);
+
     if (sendEmails) {
       await notificationService.createUserNotifications(
         orgMembers.map((member) => ({
@@ -371,6 +376,8 @@ export const projectMembershipServiceFactory = ({
       return projectUserMembershipRoleDAL.insertMany(sanitizedProjectMembershipRoles, tx);
     });
 
+    await permissionService.invalidateProjectPermissionCache(projectId);
+
     return updatedRoles;
   };
 
@@ -414,6 +421,9 @@ export const projectMembershipServiceFactory = ({
       );
       return deletedMembership;
     });
+
+    await permissionService.invalidateProjectPermissionCache(projectId);
+
     return membership;
   };
 
@@ -515,6 +525,9 @@ export const projectMembershipServiceFactory = ({
 
       return deletedMemberships;
     });
+
+    await permissionService.invalidateProjectPermissionCache(projectId);
+
     return memberships;
   };
 
diff --git a/backend/src/services/project-role/project-role-service.ts b/backend/src/services/project-role/project-role-service.ts
index dd0eecc68e..f30da21f53 100644
--- a/backend/src/services/project-role/project-role-service.ts
+++ b/backend/src/services/project-role/project-role-service.ts
@@ -35,7 +35,10 @@ type TProjectRoleServiceFactoryDep = {
   identityDAL: Pick<TIdentityDALFactory, "findById">;
   userDAL: Pick<TUserDALFactory, "findById">;
   projectDAL: Pick<TProjectDALFactory, "findProjectBySlug" | "findProjectById">;
-  permissionService: Pick<TPermissionServiceFactory, "getProjectPermission" | "getUserProjectPermission">;
+  permissionService: Pick<
+    TPermissionServiceFactory,
+    "getProjectPermission" | "getUserProjectPermission" | "invalidateProjectPermissionCache"
+  >;
   identityProjectMembershipRoleDAL: TIdentityProjectMembershipRoleDALFactory;
   projectUserMembershipRoleDAL: TProjectUserMembershipRoleDALFactory;
 };
@@ -162,6 +165,8 @@ export const projectRoleServiceFactory = ({
     });
     if (!updatedRole) throw new NotFoundError({ message: "Project role not found", name: "Update role" });
 
+    await permissionService.invalidateProjectPermissionCache(projectRole.projectId);
+
     return { ...updatedRole, permissions: unpackPermissions(updatedRole.permissions) };
   };
 
@@ -197,6 +202,8 @@ export const projectRoleServiceFactory = ({
     const deletedRole = await projectRoleDAL.deleteById(roleId);
     if (!deletedRole) throw new NotFoundError({ message: "Project role not found", name: "Delete role" });
 
+    await permissionService.invalidateProjectPermissionCache(projectRole.projectId);
+
     return { ...deletedRole, permissions: unpackPermissions(deletedRole.permissions) };
   };