diff --git a/CHANGES.md b/CHANGES.md
index 4f94355b..f44db2a9 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -4,6 +4,7 @@ CHANGELOG
 ## Unreleased
 
 * @bdeitte Fill in some missing areas for automated tests
+* @bdeitte CPU performance improvements: cache byteLength in sendMessage, use hrtime.bigint in timer functions, use Map in overrideTags
 
 ## 14.0.0 (2026-2-15)
 
diff --git a/lib/helpers.js b/lib/helpers.js
index db5d1508..4f5f2020 100644
--- a/lib/helpers.js
+++ b/lib/helpers.js
@@ -96,38 +96,41 @@ function overrideTags (parent, child, telegraf) {
     return parent;
   }
 
-  const childCopy = {};
+  const formattedChild = formatTags(child, telegraf);
+
+  const childCopy = new Map();
   const toAppend = [];
 
-  formatTags(child, telegraf).forEach(tag => {
+  formattedChild.forEach(tag => {
     const idx = typeof tag === 'string' ? tag.indexOf(':') : -1;
-    if (idx < 1) { // Not found or first character
+    if (idx < 1) {
       toAppend.push(tag);
     } else {
       const key = tag.substring(0, idx);
       const value = tag.substring(idx + 1);
-      childCopy[key] = childCopy[key] || [];
-      childCopy[key].push(value);
+      if (!childCopy.has(key)) {
+        childCopy.set(key, []);
+      }
+      childCopy.get(key).push(value);
     }
   });
 
   const result = parent.filter(tag => {
     const idx = typeof tag === 'string' ? tag.indexOf(':') : -1;
-    if (idx < 1) { // Not found or first character
+    if (idx < 1) {
       return true;
     }
-
     const key = tag.substring(0, idx);
-
-    return !childCopy.hasOwnProperty(key);
+    return !childCopy.has(key);
   });
 
-  Object.keys(childCopy).forEach(key => {
-    for (const value of childCopy[key]) {
+  for (const [key, values] of childCopy) {
+    for (const value of values) {
       result.push(`${key}:${value}`);
     }
-  });
-  return result.concat(toAppend);
+  }
+  result.push(...toAppend);
+  return result;
 }
 
 /**
diff --git a/lib/statsFunctions.js b/lib/statsFunctions.js
index 4d9dee78..86435fba 100644
--- a/lib/statsFunctions.js
+++ b/lib/statsFunctions.js
@@ -36,15 +36,11 @@ function applyStatsFns (Client) {
 
     return (...args) => {
       const ctx = createTimerContext();
-      const start = process.hrtime();
+      const start = process.hrtime.bigint();
       try {
         return func(...args, ctx);
       } finally {
-        // get duration in milliseconds
-        const durationComponents = process.hrtime(start);
-        const seconds = durationComponents[0];
-        const nanoseconds = durationComponents[1];
-        const duration = (seconds * 1000) + (nanoseconds / 1E6);
+        const duration = Number(process.hrtime.bigint() - start) / 1e6;
 
         const finalTags = mergeTags(tags, ctx.getTags(), _this.telegraf);
         _this.timing(
@@ -118,14 +114,10 @@ function applyStatsFns (Client) {
    * High-resolution timer
    */
   function hrtimer() {
-    const start = process.hrtime();
+    const start = process.hrtime.bigint();
 
     return () => {
-      const durationComponents = process.hrtime(start);
-      const seconds = durationComponents[0];
-      const nanoseconds = durationComponents[1];
-      const duration = (seconds * 1000) + (nanoseconds / 1E6);
-      return duration;
+      return Number(process.hrtime.bigint() - start) / 1e6;
     };
   }
 
diff --git a/lib/statsd.js b/lib/statsd.js
index a46d6107..43e6b8df 100644
--- a/lib/statsd.js
+++ b/lib/statsd.js
@@ -505,7 +505,7 @@ Client.prototype.sendMessage = function (message, callback, isTelemetry) {
         protocolErrorHandler(this, this.protocol, err);
       }
     } else {
-      debug('hot-shots sendMessage: successfully sent %d bytes', Buffer.byteLength(message));
+      debug('hot-shots sendMessage: successfully sent %d bytes', messageBytes);
       // Track bytes sent successfully (only for non-telemetry messages)
       if (this.telemetry && !isTelemetry) {
         this.telemetry.recordBytesSent(messageBytes);
diff --git a/package.json b/package.json
index b88c17a0..f549db36 100644
--- a/package.json
+++ b/package.json
@@ -33,6 +33,7 @@
     "coverage": "nyc --reporter=lcov --reporter=text npm test",
     "test": "mocha -R spec --timeout 5000 test/*.js",
     "lint": "eslint \"./lib/**/*.js\" \"./test/**/*.js\"",
+    "perf": "node perfTest/test.js",
     "pretest": "npm run lint"
   },
   "optionalDependencies": {
diff --git a/perfTest/test.js b/perfTest/test.js
index 09ff3c6e..553b33b4 100644
--- a/perfTest/test.js
+++ b/perfTest/test.js
@@ -1,21 +1,53 @@
-const statsD = require('../lib/statsd');
-let count = 0;
-const options = {
-    maxBufferSize: process.argv[2]
-};
-const statsd = new statsD(options);
-
-let start = new Date();
-
-function sendPacket() {
-    count++;
-    statsd.increment('abc.cde.efg.ghk.klm', 1);
-    if(count %100000 ===  0) {
-        const stop = new Date();
-        console.log(stop - start);
-        start = stop;
-    }
-    setImmediate(sendPacket);
+'use strict';
+
+const StatsD = require('../lib/statsd');
+
+const WARMUP = process.env.WARMUP ? parseInt(process.env.WARMUP) : 20000;
+const ITERS  = process.env.ITERS  ? parseInt(process.env.ITERS)  : 300000;
+
+const noTagClient = new StatsD({ mock: true });
+const globalTagClient = new StatsD({
+  mock: true,
+  globalTags: { env: 'prod', region: 'us-east-1', service: 'api' }
+});
+
+const timerWrapped = noTagClient.timer(function noop() {}, 'hot.shots.perf.timer');
+
+function bench(label, fn) {
+  noTagClient.mockBuffer = [];
+  globalTagClient.mockBuffer = [];
+
+  for (let i = 0; i < WARMUP; i++) { fn(); }
+
+  noTagClient.mockBuffer = [];
+  globalTagClient.mockBuffer = [];
+
+  const start = process.hrtime.bigint();
+  for (let i = 0; i < ITERS; i++) { fn(); }
+  const ns = Number(process.hrtime.bigint() - start);
+
+  const opsPerSec = Math.round(ITERS / (ns / 1e9));
+  console.log(`  ${label.padEnd(45)} ${opsPerSec.toLocaleString().padStart(14)} ops/sec`);
 }
 
-sendPacket();
+console.log(`\nhot-shots performance (${ITERS.toLocaleString()} iters, ${WARMUP.toLocaleString()} warmup, mock mode):\n`);
+
+bench('increment, no tags',
+  () => noTagClient.increment('hot.shots.perf.metric', 1));
+
+bench('increment, global tags only',
+  () => globalTagClient.increment('hot.shots.perf.metric', 1));
+
+bench('increment, per-metric tags (no overlap)',
+  () => noTagClient.increment('hot.shots.perf.metric', 1, { status: 'ok', host: 'web-01' }));
+
+bench('increment, per-metric + global tags (overlap)',
+  () => globalTagClient.increment('hot.shots.perf.metric', 1, { env: 'staging', version: 'v2' }));
+
+bench('timing',
+  () => noTagClient.timing('hot.shots.perf.metric', 250));
+
+bench('timer wrapper',
+  () => timerWrapped());
+
+console.log();