diff --git a/packages/metrics/src/Metrics.ts b/packages/metrics/src/Metrics.ts
index f5f40b3abe..ad9e2de7f4 100644
--- a/packages/metrics/src/Metrics.ts
+++ b/packages/metrics/src/Metrics.ts
@@ -49,10 +49,10 @@ import type {
  * These metrics can be visualized through Amazon CloudWatch Console.
  *
  * **Key features**
- * * Aggregating up to 100 metrics using a single CloudWatch EMF object (large JSON blob).
- * * Validating your metrics against common metric definitions mistakes (for example, metric unit, values, max dimensions, max metrics).
- * * Metrics are created asynchronously by the CloudWatch service. You do not need any custom stacks, and there is no impact to Lambda function latency.
- * * Creating a one-off metric with different dimensions.
+ * - Aggregating up to 100 metrics using a single CloudWatch EMF object (large JSON blob).
+ * - Validating your metrics against common metric definitions mistakes (for example, metric unit, values, max dimensions, max metrics).
+ * - Metrics are created asynchronously by the CloudWatch service. You do not need any custom stacks, and there is no impact to Lambda function latency.
+ * - Creating a one-off metric with different dimensions.
  *
  * After initializing the Metrics class, you can add metrics using the {@link Metrics.addMetric | `addMetric()`} method.
  * The metrics are stored in a buffer and are flushed when calling {@link Metrics.publishStoredMetrics | `publishStoredMetrics()`}.
@@ -1164,7 +1164,7 @@ class Metrics extends Utility implements MetricsInterface {
      * If this point is reached, it indicates timestamp was neither a valid number nor Date
      * Returning zero represents the initial date of epoch time,
      * which will be skipped by Amazon CloudWatch.
-     **/
+     */
     return 0;
   }
 
diff --git a/packages/metrics/src/middleware/middy.ts b/packages/metrics/src/middleware/middy.ts
index d06a0977e4..665261758b 100644
--- a/packages/metrics/src/middleware/middy.ts
+++ b/packages/metrics/src/middleware/middy.ts
@@ -60,7 +60,7 @@ const logMetrics = (
     };
   };
 
-  const logMetricsBefore = async (request: MiddyLikeRequest): Promise<void> => {
+  const logMetricsBefore = (request: MiddyLikeRequest) => {
     for (const metrics of metricsInstances) {
       const { throwOnEmptyMetrics, defaultDimensions, captureColdStartMetric } =
         options;
@@ -78,7 +78,7 @@ const logMetrics = (
     setCleanupFunction(request);
   };
 
-  const logMetricsAfterOrError = async (): Promise<void> => {
+  const logMetricsAfterOrError = () => {
     for (const metrics of metricsInstances) {
       metrics.publishStoredMetrics();
     }
diff --git a/packages/metrics/tests/e2e/basicFeatures.decorator.test.functionCode.ts b/packages/metrics/tests/e2e/basicFeatures.decorator.test.functionCode.ts
index aa098a4abf..5cf695bfe3 100644
--- a/packages/metrics/tests/e2e/basicFeatures.decorator.test.functionCode.ts
+++ b/packages/metrics/tests/e2e/basicFeatures.decorator.test.functionCode.ts
@@ -32,8 +32,8 @@ class Lambda implements LambdaInterface {
     defaultDimensions: JSON.parse(defaultDimensions),
     throwOnEmptyMetrics: true,
   })
-  public async handler(_event: unknown, _context: Context): Promise<void> {
-    metrics.addMetric(metricName, metricUnit, Number.parseInt(metricValue));
+  public handler(_event: unknown, _context: Context) {
+    metrics.addMetric(metricName, metricUnit, Number.parseInt(metricValue, 10));
     metrics.addDimension(
       Object.entries(JSON.parse(extraDimension))[0][0],
       Object.entries(JSON.parse(extraDimension))[0][1] as string
@@ -52,7 +52,7 @@ class Lambda implements LambdaInterface {
     metricWithItsOwnDimensions.addMetric(
       singleMetricName,
       singleMetricUnit,
-      Number.parseInt(singleMetricValue)
+      Number.parseInt(singleMetricValue, 10)
     );
   }
 }
diff --git a/packages/metrics/tests/e2e/basicFeatures.decorators.test.ts b/packages/metrics/tests/e2e/basicFeatures.decorators.test.ts
index 2858aec832..063c393494 100644
--- a/packages/metrics/tests/e2e/basicFeatures.decorators.test.ts
+++ b/packages/metrics/tests/e2e/basicFeatures.decorators.test.ts
@@ -168,7 +168,7 @@ describe('Metrics E2E tests, basic features decorator usage', () => {
         ? metricStat.Datapoints[0]
         : {};
       expect(singleDataPoint?.Sum).toBeGreaterThanOrEqual(
-        Number.parseInt(expectedMetricValue) * invocations
+        Number.parseInt(expectedMetricValue, 10) * invocations
       );
     });
   });
diff --git a/packages/metrics/tests/e2e/basicFeatures.manual.test.functionCode.ts b/packages/metrics/tests/e2e/basicFeatures.manual.test.functionCode.ts
index e72736189d..f383d0c48b 100644
--- a/packages/metrics/tests/e2e/basicFeatures.manual.test.functionCode.ts
+++ b/packages/metrics/tests/e2e/basicFeatures.manual.test.functionCode.ts
@@ -25,14 +25,11 @@ const singleMetricValue = process.env.EXPECTED_SINGLE_METRIC_VALUE ?? '2';
 
 const metrics = new Metrics({ namespace: namespace, serviceName: serviceName });
 
-export const handler = async (
-  _event: unknown,
-  _context: Context
-): Promise<void> => {
+export const handler = (_event: unknown, _context: Context) => {
   metrics.captureColdStartMetric();
   metrics.throwOnEmptyMetrics();
   metrics.setDefaultDimensions(JSON.parse(defaultDimensions));
-  metrics.addMetric(metricName, metricUnit, Number.parseInt(metricValue));
+  metrics.addMetric(metricName, metricUnit, Number.parseInt(metricValue, 10));
   metrics.addDimension(
     Object.entries(JSON.parse(extraDimension))[0][0],
     Object.entries(JSON.parse(extraDimension))[0][1] as string
@@ -46,7 +43,7 @@ export const handler = async (
   metricWithItsOwnDimensions.addMetric(
     singleMetricName,
     singleMetricUnit,
-    Number.parseInt(singleMetricValue)
+    Number.parseInt(singleMetricValue, 10)
   );
 
   metrics.publishStoredMetrics();
diff --git a/packages/metrics/tests/e2e/basicFeatures.manual.test.ts b/packages/metrics/tests/e2e/basicFeatures.manual.test.ts
index 1fb1e40528..31fb75846b 100644
--- a/packages/metrics/tests/e2e/basicFeatures.manual.test.ts
+++ b/packages/metrics/tests/e2e/basicFeatures.manual.test.ts
@@ -154,7 +154,7 @@ describe('Metrics E2E tests, manual usage', () => {
         ? metricStat.Datapoints[0]
         : {};
       expect(singleDataPoint.Sum).toBeGreaterThanOrEqual(
-        Number.parseInt(expectedMetricValue) * invocations
+        Number.parseInt(expectedMetricValue, 10) * invocations
       );
     });
   });
diff --git a/packages/metrics/tests/helpers/metricsUtils.ts b/packages/metrics/tests/helpers/metricsUtils.ts
index 35bf3407d7..78718650a4 100644
--- a/packages/metrics/tests/helpers/metricsUtils.ts
+++ b/packages/metrics/tests/helpers/metricsUtils.ts
@@ -6,7 +6,7 @@ import {
 } from '@aws-sdk/client-cloudwatch';
 import promiseRetry from 'promise-retry';
 
-const getMetrics = async (
+const getMetrics = (
   cloudWatchClient: CloudWatchClient,
   namespace: string,
   metric: string,
diff --git a/packages/metrics/tests/unit/logMetrics.test.ts b/packages/metrics/tests/unit/logMetrics.test.ts
index 97c6ba7be9..62ec0ed77c 100644
--- a/packages/metrics/tests/unit/logMetrics.test.ts
+++ b/packages/metrics/tests/unit/logMetrics.test.ts
@@ -1,3 +1,4 @@
+import { setTimeout } from 'node:timers/promises';
 import { cleanupMiddlewares } from '@aws-lambda-powertools/commons';
 import middy from '@middy/core';
 import type { Context } from 'aws-lambda';
@@ -39,6 +40,7 @@ describe('LogMetrics decorator & Middy.js middleware', () => {
 
       @metrics.logMetrics({ captureColdStartMetric: true })
       async handler(_event: unknown, _context: Context) {
+        await setTimeout(0); // Simulate some async operation
         this.addGreetingMetric();
       }
 
@@ -105,6 +107,7 @@ describe('LogMetrics decorator & Middy.js middleware', () => {
 
       @metrics.logMetrics({ captureColdStartMetric: true })
       async handler(_event: unknown, _context: Context) {
+        await setTimeout(0); // Simulate some async operation
         this.addGreetingMetric();
       }
 
@@ -150,6 +153,7 @@ describe('LogMetrics decorator & Middy.js middleware', () => {
 
       @metrics.logMetrics({ captureColdStartMetric: true })
       async handler(_event: unknown, _context: Context) {
+        await setTimeout(0); // Simulate some async operation
         this.addGreetingMetric();
       }
 
@@ -184,6 +188,7 @@ describe('LogMetrics decorator & Middy.js middleware', () => {
     });
     vi.spyOn(metrics, 'publishStoredMetrics');
     const handler = middy(async () => {
+      await setTimeout(0); // Simulate some async operation
       metrics.addMetric('greetings', MetricUnit.Count, 1);
     }).use(logMetrics(metrics, { captureColdStartMetric: true }));
 
@@ -210,7 +215,7 @@ describe('LogMetrics decorator & Middy.js middleware', () => {
     });
 
     vi.spyOn(metrics, 'publishStoredMetrics');
-    const handler = middy(async () => {
+    const handler = middy(() => {
       metrics.addMetric('greetings', MetricUnit.Count, 1);
     }).use(logMetrics(metrics, { captureColdStartMetric: true }));
 
@@ -238,7 +243,7 @@ describe('LogMetrics decorator & Middy.js middleware', () => {
     });
 
     vi.spyOn(metrics, 'publishStoredMetrics');
-    const handler = middy(async () => {
+    const handler = middy(() => {
       metrics.addMetric('greetings', MetricUnit.Count, 1);
     }).use(logMetrics(metrics, { captureColdStartMetric: true }));
 
@@ -266,6 +271,7 @@ describe('LogMetrics decorator & Middy.js middleware', () => {
     class Test {
       @metrics.logMetrics({ defaultDimensions: { environment: 'test' } })
       async handler(_event: unknown, _context: Context) {
+        await setTimeout(0); // Simulate some async operation
         metrics.addMetric('test', MetricUnit.Count, 1);
       }
     }
@@ -295,6 +301,7 @@ describe('LogMetrics decorator & Middy.js middleware', () => {
     });
     vi.spyOn(metrics, 'publishStoredMetrics');
     const handler = middy(async () => {
+      await setTimeout(0); // Simulate some async operation
       metrics.addMetric('greetings', MetricUnit.Count, 1);
     }).use(
       logMetrics(metrics, {
@@ -328,6 +335,7 @@ describe('LogMetrics decorator & Middy.js middleware', () => {
     class Test {
       @metrics.logMetrics()
       async handler(_event: unknown, _context: Context) {
+        await setTimeout(0); // Simulate some async operation
         throw new Error('Something went wrong');
       }
     }
@@ -349,6 +357,7 @@ describe('LogMetrics decorator & Middy.js middleware', () => {
     class Test {
       @metrics.logMetrics({ throwOnEmptyMetrics: true })
       async handler(_event: unknown, _context: Context) {
+        await setTimeout(0); // Simulate some async operation
         return 'Hello, world!';
       }
     }
@@ -367,12 +376,12 @@ describe('LogMetrics decorator & Middy.js middleware', () => {
       singleMetric: false,
       namespace: DEFAULT_NAMESPACE,
     });
-    const handler = middy(async () => {}).use(
-      logMetrics([metrics], { throwOnEmptyMetrics: true })
-    );
+    const handler = middy(async () => {
+      await setTimeout(0); // Simulate some async operation
+    }).use(logMetrics([metrics], { throwOnEmptyMetrics: true }));
 
     // Act & Assess
-    expect(() => handler({}, {} as Context)).rejects.toThrowError(
+    await expect(() => handler({}, {} as Context)).rejects.toThrowError(
       'The number of metrics recorded must be higher than zero'
     );
   });