diff --git a/runtime/backend/src/common/schedulers/ValidateChallengeScheduler.ts b/runtime/backend/src/common/schedulers/ValidateChallengeScheduler.ts
index 030a7b6e..49c0ce4c 100644
--- a/runtime/backend/src/common/schedulers/ValidateChallengeScheduler.ts
+++ b/runtime/backend/src/common/schedulers/ValidateChallengeScheduler.ts
@@ -149,6 +149,7 @@ export class ValidateChallengeScheduler {
     } catch (err) {
       // if challenge isn't on chain - print info to the console
       this.logger.error("failed to validate challenge", err);
+      throw err;
     }
   }
 
diff --git a/runtime/backend/tests/unit/common/gateways/AuthGateway.spec.ts b/runtime/backend/tests/unit/common/gateways/AuthGateway.spec.ts
index 05f06397..26570208 100644
--- a/runtime/backend/tests/unit/common/gateways/AuthGateway.spec.ts
+++ b/runtime/backend/tests/unit/common/gateways/AuthGateway.spec.ts
@@ -14,6 +14,7 @@ import { EventEmitter2 } from "@nestjs/event-emitter";
 import { SchedulerRegistry } from "@nestjs/schedule";
 import { ConfigService } from "@nestjs/config";
 import { JwtService } from "@nestjs/jwt";
+import { getModelToken } from "@nestjs/mongoose";
 
 // internal dependencies
 import { ValidateChallengeScheduler } from "../../../../src/common/schedulers/ValidateChallengeScheduler";
@@ -24,7 +25,6 @@ import { AccountsService } from "../../../../src/common/services/AccountsService
 import { ChallengesService } from "../../../../src/common/services/ChallengesService";
 import { QueryService } from "../../../../src/common/services/QueryService";
 import { MockModel } from "../../../mocks/global";
-import { getModelToken } from "@nestjs/mongoose";
 
 describe("common/AuthGateway", () => {
   let authGateway: AuthGateway;
diff --git a/runtime/backend/tests/unit/common/schedulers/ValidateChallengeScheduler.spec.ts b/runtime/backend/tests/unit/common/schedulers/ValidateChallengeScheduler.spec.ts
new file mode 100644
index 00000000..ca861b99
--- /dev/null
+++ b/runtime/backend/tests/unit/common/schedulers/ValidateChallengeScheduler.spec.ts
@@ -0,0 +1,186 @@
+/**
+ * This file is part of dHealth dApps Framework shared under LGPL-3.0
+ * Copyright (C) 2022-present dHealth Network, All rights reserved.
+ *
+ * @package     dHealth dApps Framework
+ * @subpackage  Backend
+ * @author      dHealth Network <devs@dhealth.foundation>
+ * @license     LGPL-3.0
+ */
+
+// external dependencies
+import { TestingModule, Test } from "@nestjs/testing";
+import { SchedulerRegistry } from "@nestjs/schedule";
+import { ConfigService } from "@nestjs/config";
+import { JwtService } from "@nestjs/jwt";
+import { EventEmitter2 } from "@nestjs/event-emitter";
+import { getModelToken } from "@nestjs/mongoose";
+
+// internal dependencies
+import { AuthService } from "../../../../src/common/services/AuthService";
+import { NetworkService } from "../../../../src/common/services/NetworkService";
+import { AccountsService } from "../../../../src/common/services/AccountsService";
+import { ChallengesService } from "../../../../src/common/services/ChallengesService";
+import { QueryService } from "../../../../src/common/services/QueryService";
+import { MockModel } from "../../../mocks/global";
+import { ValidateChallengeScheduler } from "../../../../src/common/schedulers/ValidateChallengeScheduler";
+
+describe("common/ValidateChallengeScheduler", () => {
+  let validateChallengeScheduler: ValidateChallengeScheduler;
+
+  beforeEach(async () => {
+    const module: TestingModule = await Test.createTestingModule({
+      providers: [
+        ValidateChallengeScheduler,
+        SchedulerRegistry,
+        EventEmitter2,
+        AuthService,
+        ConfigService,
+        NetworkService,
+        AccountsService,
+        ChallengesService,
+        QueryService,
+        JwtService,
+        {
+          provide: getModelToken("Account"),
+          useValue: MockModel,
+        }, // requirement from AccountsService
+        {
+          provide: getModelToken("AuthChallenge"),
+          useValue: MockModel,
+        },
+        {
+          provide: getModelToken("AccountSession"),
+          useValue: MockModel,
+        }, // requirement from AuthService
+      ],
+    }).compile();
+
+    validateChallengeScheduler = module.get<ValidateChallengeScheduler>(
+      ValidateChallengeScheduler,
+    );
+  });
+
+  it("should be defined", () => {
+    expect(validateChallengeScheduler).toBeDefined();
+  });
+
+  describe("constructor()", () => {
+    it("should initialize cronjob", () => {
+      expect((validateChallengeScheduler as any).job).not.toBe(null);
+      expect((validateChallengeScheduler as any).job).not.toBe(undefined);
+    });
+
+    it("should add cron to nest registry", () => {
+      const mockedFn = jest.fn();
+
+      (validateChallengeScheduler as any).schedulerRegistry = {
+        addCronJob: mockedFn,
+      };
+
+      new ValidateChallengeScheduler(
+        (validateChallengeScheduler as any).schedulerRegistry,
+        {} as AuthService,
+        {} as EventEmitter2,
+      );
+
+      expect(mockedFn).toBeCalledTimes(1);
+    });
+
+    it("should initialize logger", () => {
+      expect((validateChallengeScheduler as any).logger).not.toBe(null);
+      expect((validateChallengeScheduler as any).logger).not.toBe(undefined);
+    });
+  });
+
+  describe("startCronJob()", () => {
+    it("should start cronjob", () => {
+      const mockFn = jest.fn();
+
+      (validateChallengeScheduler as any).job = {
+        start: mockFn,
+      };
+
+      validateChallengeScheduler.startCronJob("someFakeChallenge");
+
+      expect(mockFn).toBeCalledTimes(1);
+    });
+
+    it("should assign argument to challenge prop", () => {
+      validateChallengeScheduler.startCronJob("someFakeChallenge");
+
+      expect((validateChallengeScheduler as any).challenge).toBe(
+        "someFakeChallenge",
+      );
+    });
+
+    it("should start stop timeout", () => {
+      validateChallengeScheduler.startCronJob("someFakeChallenge");
+
+      expect((validateChallengeScheduler as any).stopCronJobTimeout).not.toBe(
+        null,
+      );
+      expect((validateChallengeScheduler as any).stopCronJobTimeout).not.toBe(
+        undefined,
+      );
+    });
+  });
+
+  describe("stopCronJob()", () => {
+    it("should stop cronjob", () => {
+      const mockFn = jest.fn();
+      (validateChallengeScheduler as any).job = {
+        stop: mockFn,
+      };
+
+      (validateChallengeScheduler as any).stopCronJob();
+
+      expect(mockFn).toBeCalledTimes(1);
+    });
+
+    it("should reset challenge string", () => {
+      (validateChallengeScheduler as any).stopCronJob();
+
+      expect((validateChallengeScheduler as any).challenge).toBe("");
+    });
+
+    it("should clear stopTimeout", () => {
+      const clearTimeout = jest.fn();
+      (validateChallengeScheduler as any).startCronJob();
+      (validateChallengeScheduler as any).stopCronJob();
+
+      expect((validateChallengeScheduler as any).stopCronJobTimeout).not.toBe(
+        undefined,
+      );
+    });
+  });
+
+  describe("validate()", () => {
+    it("should call validateChallenge", () => {
+      const mockedValidate = jest.fn();
+
+      (validateChallengeScheduler as any).authService = {
+        validateChallenge: mockedValidate,
+      };
+
+      (validateChallengeScheduler as any).validate();
+
+      expect(mockedValidate).toBeCalled();
+    });
+
+    it("should log error if challenge invalid", () => {
+      (validateChallengeScheduler as any).challenge = "invalidChallenge";
+
+      expect((validateChallengeScheduler as any).validate()).toThrowError();
+    });
+
+    // it("should stop cronJob", () => {
+    //   const mockedFn = jest.fn();
+    //   (validateChallengeScheduler as any).stopCronJob = mockedFn;
+
+    //   (validateChallengeScheduler as any).validate();
+
+    //   expect(mockedFn).toBeCalled();
+    // });
+  });
+});