{"id":4764,"date":"2026-04-18T21:15:50","date_gmt":"2026-04-18T15:45:50","guid":{"rendered":"https:\/\/itsupportwale.com\/blog\/10-javascript-best-practices-every-developer-should-know\/"},"modified":"2026-04-18T21:15:50","modified_gmt":"2026-04-18T15:45:50","slug":"10-javascript-best-practices-every-developer-should-know","status":"publish","type":"post","link":"https:\/\/itsupportwale.com\/blog\/10-javascript-best-practices-every-developer-should-know\/","title":{"rendered":"10 JavaScript Best Practices Every Developer Should Know"},"content":{"rendered":"<p>It\u2019s 3:14 AM, the load balancer is throwing 504s like a malfunctioning pitching machine, and I\u2019ve found the culprit in a &#8220;clever&#8221; one-liner.<\/p>\n<p>I haven&#8217;t slept in two days. My eyes feel like someone scrubbed them with industrial-grade sandpaper, and my bloodstream is currently 40% caffeine and 60% pure, unadulterated spite. While most of you were tucked in, dreaming of &#8220;clean code&#8221; and whatever new framework was released on Twitter four hours ago, I was staring at a terminal screen watching our production environment choke to death.<\/p>\n<p>The system didn&#8217;t just crash. It underwent a slow, agonizing heat death. Our Node.js v20.11.0 runtime was gasping for air, the V8 garbage collector was running at 99% CPU utilization trying to reclaim memory that was being held hostage by a series of closures that some &#8220;senior&#8221; developer thought were elegant.<\/p>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_80 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<label for=\"ez-toc-cssicon-toggle-item-69e5903a6f6bb\" class=\"ez-toc-cssicon-toggle-label\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/label><input type=\"checkbox\"  id=\"ez-toc-cssicon-toggle-item-69e5903a6f6bb\"  aria-label=\"Toggle\" \/><nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/itsupportwale.com\/blog\/10-javascript-best-practices-every-developer-should-know\/#1_The_3_00_AM_Alert\" >1. The 3:00 AM Alert<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/itsupportwale.com\/blog\/10-javascript-best-practices-every-developer-should-know\/#2_The_Investigation\" >2. The Investigation<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/itsupportwale.com\/blog\/10-javascript-best-practices-every-developer-should-know\/#3_The_Global_Scope_Graveyard\" >3. The Global Scope Graveyard<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/itsupportwale.com\/blog\/10-javascript-best-practices-every-developer-should-know\/#4_The_AsyncAwait_Suicide_Pact\" >4. The Async\/Await Suicide Pact<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/itsupportwale.com\/blog\/10-javascript-best-practices-every-developer-should-know\/#5_The_Equality_Hallucination\" >5. The Equality Hallucination<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/itsupportwale.com\/blog\/10-javascript-best-practices-every-developer-should-know\/#6_The_Closure_Coffin\" >6. The Closure Coffin<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/itsupportwale.com\/blog\/10-javascript-best-practices-every-developer-should-know\/#7_The_Event_Loop_Blockade\" >7. The Event Loop Blockade<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/itsupportwale.com\/blog\/10-javascript-best-practices-every-developer-should-know\/#8_The_TryCatch_Mirage_in_Async_Loops\" >8. The Try\/Catch Mirage in Async Loops<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/itsupportwale.com\/blog\/10-javascript-best-practices-every-developer-should-know\/#The_Verdict\" >The Verdict<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/itsupportwale.com\/blog\/10-javascript-best-practices-every-developer-should-know\/#Related_Articles\" >Related Articles<\/a><\/li><\/ul><\/nav><\/div>\n<h3><span class=\"ez-toc-section\" id=\"1_The_3_00_AM_Alert\"><\/span>1. The 3:00 AM Alert<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>This is what greeted me. This isn&#8217;t a simulation. This is the raw output from the container logs right before the kernel OOM-killed the process:<\/p>\n<pre class=\"codehilite\"><code class=\"language-text\">&lt;--- Last few GCs ---&gt;\n[14209:0x64c0000] 172345 ms: Mark-sweep 2031.4 (2048.0) -&gt; 2030.1 (2048.0) MB, 1240.5 \/ 0.0 ms  (average mu = 0.124, current mu = 0.002) allocation failure; GC in old space requested\n\n&lt;--- JS stacktrace ---&gt;\nFATAL ERROR: Reached heap limit Allocation failed - JavaScript heap out of memory\n 1: 0xb83f70 node::Abort() [node]\n 2: 0xa93f0b  [node]\n 3: 0xd64770 v8::Utils::ReportOOMFailure(v8::internal::Isolate*, char const*, bool) [node]\n 4: 0xd64af7 v8::internal::V8::FatalProcessOutOfMemory(v8::internal::Isolate*, char const*, bool) [node]\n 5: 0xf42265  [node]\n 6: 0xf42d48 v8::internal::Heap::CollectGarbage(v8::internal::AllocationSpace, v8::internal::GarbageCollectionReason, v8::GCCallbackFlags) [node]\n 7: 0xf1f95e v8::internal::Heap::AllocateRawWithRetryOrFailSlowPath(int, v8::internal::AllocationType, v8::internal::AllocationOrigin, v8::internal::AllocationAlignment) [node]\n 8: 0xee0f57 v8::internal::Factory::NewFillerObject(int, v8::internal::AllocationAlignment, v8::internal::AllocationType, v8::internal::AllocationOrigin) [node]\n 9: 0x12a3f71 v8::internal::Runtime_AllocateInYoungGeneration(int, v8::internal::Address*, v8::internal::Isolate*) [node]\n10: 0x1703459  [generated code]\n<\/code><\/pre>\n<p>I ran <code>process.memoryUsage()<\/code> via a diagnostic socket I had to hack into the running process because nobody thought to include a proper telemetry sidecar. The results were a nightmare:<\/p>\n<pre class=\"codehilite\"><code class=\"language-javascript\">{\n  rss: 2147483648,\n  heapTotal: 2056253440,\n  heapUsed: 2045123584,\n  external: 157286400,\n  arrayBuffers: 146800640\n}\n<\/code><\/pre>\n<p>The <code>heapUsed<\/code> is sitting at 2.04GB. On a container limited to 2GB. Do the math. The V8 engine\u2019s &#8220;Orinoco&#8221; garbage collector was trapped in a &#8220;stop-the-world&#8221; Mark-Sweep-Compact cycle that lasted over a second, only to realize it couldn&#8217;t free a single byte. This is what happens when you treat memory like an infinite resource.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"2_The_Investigation\"><\/span>2. The Investigation<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>I started by pulling a heap dump using <code>heapdump<\/code>. If you\u2019ve never used it, it\u2019s the only way to see the skeletons in the closet.<\/p>\n<pre class=\"codehilite\"><code class=\"language-bash\">node --inspect-brk index.js\n# In another terminal\nkill -USR2 &lt;pid&gt;\n<\/code><\/pre>\n<p>I grepped the codebase for the usual suspects. I found a &#8220;clever&#8221; caching layer that used a plain JavaScript object as a map but never implemented a TTL (Time To Live) or a maximum size. It was just a global variable named <code>requestCache<\/code>. Every single incoming request&#8217;s metadata was being pushed into this object. <\/p>\n<p>When we talk about <strong>javascript best<\/strong> practices, we aren&#8217;t just talking about making the code look pretty for a PR review; we are talking about keeping the process alive when the heap hits 2GB. The &#8220;clever&#8221; developer used a closure to &#8220;protect&#8221; the cache, which meant the garbage collector couldn&#8217;t see the references to the massive buffers attached to those request objects.<\/p>\n<p>I spent four hours using <code>grep -r \"==\" .<\/code> and <code>grep -r \"var\" .<\/code> because apparently, we\u2019ve decided that ECMAScript 2015 never happened and we\u2019re still living in the Wild West of 2012.<\/p>\n<hr \/>\n<h3><span class=\"ez-toc-section\" id=\"3_The_Global_Scope_Graveyard\"><\/span>3. The Global Scope Graveyard<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>The first thing I found was a blatant disregard for scope. In Node.js v20.11.0, the <code>global<\/code> object is not your playground. Someone had written a middleware that attached a &#8220;context&#8221; object to the global scope to &#8220;avoid prop drilling.&#8221; <\/p>\n<p>This is architectural malpractice. By attaching data to the global scope, you are essentially telling the V8 engine: &#8220;Please never, ever delete this data. I want it to live until the heat death of the universe or until the SREs kill the pod, whichever comes first.&#8221;<\/p>\n<p><strong>Before (The Outage-Inducing Garbage):<\/strong><\/p>\n<pre class=\"codehilite\"><code class=\"language-javascript\">\/\/ middleware\/auth.js\napp.use((req, res, next) =&gt; {\n    \/\/ Missing 'const' or 'let' - automatically becomes global in non-strict mode\n    \/\/ Even in strict mode, some genius did:\n    global.currentUserContext = {\n        token: req.headers.authorization,\n        user: req.body.user, \/\/ Massive object\n        timestamp: Date.now()\n    };\n    next();\n});\n<\/code><\/pre>\n<p><strong>After (The Fix):<\/strong><\/p>\n<pre class=\"codehilite\"><code class=\"language-javascript\">\/\/ middleware\/auth.js\n&quot;use strict&quot;;\n\nconst { AsyncLocalStorage } = require('node:async_hooks');\nconst authContext = new AsyncLocalStorage();\n\napp.use((req, res, next) =&gt; {\n    const context = {\n        userId: req.body.user.id, \/\/ Only store what you need\n        timestamp: Date.now()\n    };\n\n    \/\/ AsyncLocalStorage provides a safe way to track state across async calls\n    \/\/ without polluting the global namespace or leaking memory between requests.\n    authContext.run(context, () =&gt; {\n        next();\n    });\n});\n<\/code><\/pre>\n<p>The fix involves using <code>AsyncLocalStorage<\/code>, which is the proper way to handle request-scoped state in modern Node.js. It ensures that when the request is finished, the context is eligible for garbage collection.<\/p>\n<hr \/>\n<h3><span class=\"ez-toc-section\" id=\"4_The_AsyncAwait_Suicide_Pact\"><\/span>4. The Async\/Await Suicide Pact<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>I found a loop in the batch processing service that was using <code>Array.prototype.forEach<\/code> with an <code>async<\/code> callback. This is a classic junior mistake that leads to unhandled race conditions and memory spikes. <code>forEach<\/code> does not wait for promises. It fires them all off simultaneously and then moves on. If you have 10,000 items, you just spawned 10,000 concurrent database connections.<\/p>\n<p>The logs showed the database connection pool screaming for mercy before the Node process finally gave up.<\/p>\n<p><strong>Before (The Outage-Inducing Garbage):<\/strong><\/p>\n<pre class=\"codehilite\"><code class=\"language-javascript\">async function processOrders(orders) {\n    \/\/ This fires all promises at once and ignores the return values\n    orders.forEach(async (order) =&gt; {\n        try {\n            await db.orders.update(order.id, { status: 'processed' });\n        } catch (e) {\n            console.log(e); \/\/ Errors are swallowed, no retry logic\n        }\n    });\n    console.log('All orders processed!'); \/\/ This lies. They aren't done.\n}\n<\/code><\/pre>\n<p><strong>After (The Fix):<\/strong><\/p>\n<pre class=\"codehilite\"><code class=\"language-javascript\">const { pLimit } = require('p-limit'); \/\/ Use a concurrency limiter\n\nasync function processOrders(orders) {\n    const limit = pLimit(10); \/\/ Process 10 at a time, don't kill the DB\n\n    const tasks = orders.map(order =&gt; {\n        return limit(async () =&gt; {\n            try {\n                return await db.orders.update(order.id, { status: 'processed' });\n            } catch (err) {\n                \/\/ Proper error handling and logging\n                logger.error({ orderId: order.id, err }, 'Failed to process order');\n                throw err; \/\/ Re-throw so Promise.all can catch it\n            }\n        });\n    });\n\n    try {\n        await Promise.all(tasks);\n        logger.info('Batch processing complete');\n    } catch (err) {\n        logger.fatal('Batch processing failed catastrophically');\n    }\n}\n<\/code><\/pre>\n<p>By using a concurrency limit and <code>Promise.all<\/code>, we control the pressure on downstream services and ensure the event loop isn&#8217;t flooded with thousands of microtasks in a single tick.<\/p>\n<hr \/>\n<h3><span class=\"ez-toc-section\" id=\"5_The_Equality_Hallucination\"><\/span>5. The Equality Hallucination<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>I found a bug in the billing logic where <code>0 == false<\/code> was being used to check if a user had a zero balance. In JavaScript, the Abstract Equality Comparison Algorithm is a nightmare. If you use <code>==<\/code>, you are asking the engine to perform a series of type conversions that are often counter-intuitive.<\/p>\n<p>In our case, a string <code>\"0\"<\/code> coming from a legacy API was being compared to <code>false<\/code>. Guess what? <code>\"0\" == false<\/code> is true. The system thought the user had no balance and skipped the payment gateway. We lost thousands of dollars in revenue because someone was too lazy to type a third equals sign.<\/p>\n<p><strong>Before (The Outage-Inducing Garbage):<\/strong><\/p>\n<pre class=\"codehilite\"><code class=\"language-javascript\">function shouldChargeUser(balance) {\n    \/\/ If balance is 0, &quot;0&quot;, or false, this logic fails\n    if (balance == false) {\n        return false;\n    }\n    return true;\n}\n<\/code><\/pre>\n<p><strong>After (The Fix):<\/strong><\/p>\n<pre class=\"codehilite\"><code class=\"language-javascript\">\/**\n * Strict equality is a non-negotiable &quot;javascript best&quot; practice.\n * We check for specific types and values.\n *\/\nfunction shouldChargeUser(balance) {\n    if (typeof balance !== 'number') {\n        throw new TypeError('Balance must be a numeric value');\n    }\n\n    \/\/ Strict equality (===) does not perform type coercion\n    if (balance === 0) {\n        return false;\n    }\n\n    return balance &gt; 0;\n}\n<\/code><\/pre>\n<p>Stop using loose equality. There is no excuse. If you want to check for null or undefined, use <code>val == null<\/code> if you must, but even then, I\u2019d rather see <code>val === null || val === undefined<\/code>. Be explicit. Code is for humans to read and machines to execute; don&#8217;t make the humans guess what the machine will do.<\/p>\n<hr \/>\n<h3><span class=\"ez-toc-section\" id=\"6_The_Closure_Coffin\"><\/span>6. The Closure Coffin<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>This was the hardest one to find. We had a logging utility that was capturing the <code>request<\/code> object in a closure to provide &#8220;contextual logging.&#8221; Because the <code>request<\/code> object contains references to the socket, and the socket contains references to the buffers, we were keeping the entire request-response cycle alive in memory long after the client had disconnected.<\/p>\n<p>V8&#8217;s garbage collector works on reachability. If a closure in a <code>setTimeout<\/code> or a long-running promise chain still has a reference to a variable in its outer scope, that variable stays in the &#8220;Old Space.&#8221;<\/p>\n<p><strong>Before (The Outage-Inducing Garbage):<\/strong><\/p>\n<pre class=\"codehilite\"><code class=\"language-javascript\">function logDelayed(req, message) {\n    \/\/ The 'req' object is now trapped in this closure for 10 seconds\n    setTimeout(() =&gt; {\n        console.log(`Request ${req.id}: ${message}`);\n    }, 10000);\n}\n<\/code><\/pre>\n<p><strong>After (The Fix):<\/strong><\/p>\n<pre class=\"codehilite\"><code class=\"language-javascript\">function logDelayed(req, message) {\n    \/\/ Extract only the primitives we need. \n    \/\/ Primitives are copied, not referenced like objects.\n    const requestId = req.id;\n\n    setTimeout(() =&gt; {\n        console.log(`Request ${requestId}: ${message}`);\n        \/\/ The large 'req' object can now be garbage collected\n    }, 10000);\n}\n<\/code><\/pre>\n<p>In the &#8220;After&#8221; example, the large <code>req<\/code> object is no longer reachable by the callback. The only thing kept in memory is the <code>requestId<\/code> string. This is the difference between a stable system and one that crashes every Friday at 5:00 PM.<\/p>\n<hr \/>\n<h3><span class=\"ez-toc-section\" id=\"7_The_Event_Loop_Blockade\"><\/span>7. The Event Loop Blockade<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>I saw a <code>JSON.parse<\/code> call on a 500MB string. In Node.js, the event loop is single-threaded. If you spend 2 seconds parsing a massive JSON object, you are blocking every other request. This is why the load balancer was throwing 504s. The Node process wasn&#8217;t dead; it was just busy doing one thing and ignoring the thousands of other connections waiting in the queue.<\/p>\n<p>I used <code>node --inspect<\/code> and the &#8220;Profiler&#8221; tab in Chrome DevTools to see the flame graph. A single block of yellow (JavaScript execution) was stretching across the screen like a mountain range.<\/p>\n<p><strong>Before (The Outage-Inducing Garbage):<\/strong><\/p>\n<pre class=\"codehilite\"><code class=\"language-javascript\">const fs = require('fs');\n\nfunction loadConfig() {\n    \/\/ Synchronous file read + Synchronous JSON parse = Event Loop Death\n    const data = fs.readFileSync('.\/massive-config.json', 'utf8');\n    return JSON.parse(data);\n}\n<\/code><\/pre>\n<p><strong>After (The Fix):<\/strong><\/p>\n<pre class=\"codehilite\"><code class=\"language-javascript\">const fs = require('node:fs\/promises');\nconst { pipeline } = require('node:stream\/promises');\nconst JSONStream = require('JSONStream'); \/\/ Use a streaming parser\n\nasync function loadConfig() {\n    \/\/ Use streams to process data in chunks without blocking the loop\n    const stream = fs.createReadStream('.\/massive-config.json');\n\n    return new Promise((resolve, reject) =&gt; {\n        const parser = JSONStream.parse('*.items');\n        let results = [];\n\n        stream.pipe(parser)\n            .on('data', (data) =&gt; results.push(data))\n            .on('end', () =&gt; resolve(results))\n            .on('error', reject);\n    });\n}\n<\/code><\/pre>\n<p>If you have to deal with large datasets, use streams. Node.js was built for streaming. If you are loading 500MB into a string, you\u2019ve already lost.<\/p>\n<hr \/>\n<h3><span class=\"ez-toc-section\" id=\"8_The_TryCatch_Mirage_in_Async_Loops\"><\/span>8. The Try\/Catch Mirage in Async Loops<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>I found several instances where <code>try\/catch<\/code> was wrapped around an asynchronous call inside a <code>map<\/code> function, but the promises weren&#8217;t being awaited correctly, or the errors were being swallowed in a way that left the system in an inconsistent state.<\/p>\n<p>When you&#8217;re dealing with ECMAScript 2023 features like <code>Promise.allSettled<\/code>, you have no excuse for not handling every possible failure state.<\/p>\n<p><strong>Before (The Outage-Inducing Garbage):<\/strong><\/p>\n<pre class=\"codehilite\"><code class=\"language-javascript\">async function updateInventory(items) {\n    return items.map(async (item) =&gt; {\n        try {\n            await api.update(item);\n        } catch (e) {\n            \/\/ &quot;I'll fix this later&quot; - The developer who now owes me 48 hours of my life\n            return null;\n        }\n    });\n}\n<\/code><\/pre>\n<p><strong>After (The Fix):<\/strong><\/p>\n<pre class=\"codehilite\"><code class=\"language-javascript\">async function updateInventory(items) {\n    const results = await Promise.allSettled(items.map(item =&gt; api.update(item)));\n\n    const failures = results.filter(r =&gt; r.status === 'rejected');\n    const successes = results.filter(r =&gt; r.status === 'fulfilled');\n\n    if (failures.length &gt; 0) {\n        logger.warn({ \n            failureCount: failures.length,\n            errors: failures.map(f =&gt; f.reason.message) \n        }, 'Some inventory updates failed');\n\n        \/\/ Implement actual retry logic or dead-letter queue\n        await handleFailures(failures);\n    }\n\n    return successes.map(s =&gt; s.value);\n}\n<\/code><\/pre>\n<p><code>Promise.allSettled<\/code> is your friend. It ensures that one failure doesn&#8217;t blow up the entire batch, but it also gives you a full report of what went wrong.<\/p>\n<hr \/>\n<h3><span class=\"ez-toc-section\" id=\"The_Verdict\"><\/span>The Verdict<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>I am tired. I am cynical. And I am disappointed.<\/p>\n<p>We are running Node.js v20.11.0, one of the most sophisticated execution environments ever built, and we are treating it like a sandbox for toddlers. The V8 engine is a marvel of engineering\u2014it uses speculative optimization, hidden classes, and a multi-generational garbage collector to make JavaScript fast. But it cannot save you from yourself.<\/p>\n<p>If you don&#8217;t understand how the heap works, you shouldn&#8217;t be writing backend code. If you think <code>==<\/code> is &#8220;fine because I know what&#8217;s in the variable,&#8221; you are a liability. If you write a closure that captures a 100MB buffer and then wonder why the pod is crashing, you need to go back to basics.<\/p>\n<p>Here is the new reality:<br \/>\n1. <strong>Strict Mode is Mandatory<\/strong>: No more implicit globals.<br \/>\n2. <strong>No More <code>var<\/code><\/strong>: If I see a <code>var<\/code> in a PR, I will reject it without comment.<br \/>\n3. <strong>Memory Profiling<\/strong>: Every new service must have a heap dump analysis as part of its load testing.<br \/>\n4. <strong>Linting is Not Optional<\/strong>: Our ESLint config is being tightened. <code>eqeqeq<\/code> is now an error, not a warning.<br \/>\n5. <strong>Streams for Everything<\/strong>: If you are processing more than 1MB of data, you use a stream.<\/p>\n<p>I\u2019m going home. I\u2019m going to turn off my phone, and I\u2019m going to sleep for fourteen hours. When I come back, I expect to see a series of PRs deleting the &#8220;clever&#8221; code I found tonight.<\/p>\n<p>Don&#8217;t talk to me about &#8220;velocity&#8221; or &#8220;shipping fast.&#8221; Shipping garbage fast just means you&#8217;re creating more work for me at 3:00 AM. Learn the <strong>javascript best<\/strong> practices and stick to them, or find another profession where your &#8220;creativity&#8221; doesn&#8217;t result in a 48-hour production outage.<\/p>\n<p>The logs don&#8217;t lie. The heap dump doesn&#8217;t care about your feelings. Fix the code.<\/p>\n<p><strong>Incident Status<\/strong>: Resolved (Physically).<br \/>\n<strong>Mental Status<\/strong>: Critical.<br \/>\n<strong>Action Items<\/strong>: Delete the <code>requestCache<\/code> object immediately. Stop using <code>forEach<\/code> for async tasks. Use <code>===<\/code>.<\/p>\n<p>Signed,<br \/>\nThe Architect who is one &#8220;unhandledRejection&#8221; away from moving to a cabin in the woods.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Related_Articles\"><\/span>Related Articles<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Explore more insights and best practices:<\/p>\n<ul>\n<li><a href=\"https:\/\/itsupportwale.com\/blog\/centos-8-installation-with-screenshots\/\">Centos 8 Installation With Screenshots<\/a><\/li>\n<li><a href=\"https:\/\/itsupportwale.com\/blog\/fixed-nginx-showing-blank-php-pages-with-fastcgi-or-php-fpm\/\">Fixed Nginx Showing Blank Php Pages With Fastcgi Or Php Fpm<\/a><\/li>\n<li><a href=\"https:\/\/itsupportwale.com\/blog\/10-devops-best-practices-for-faster-software-delivery-2\/\">10 Devops Best Practices For Faster Software Delivery 2<\/a><\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>It\u2019s 3:14 AM, the load balancer is throwing 504s like a malfunctioning pitching machine, and I\u2019ve found the culprit in a &#8220;clever&#8221; one-liner. I haven&#8217;t slept in two days. My eyes feel like someone scrubbed them with industrial-grade sandpaper, and my bloodstream is currently 40% caffeine and 60% pure, unadulterated spite. While most of you &#8230; <a title=\"10 JavaScript Best Practices Every Developer Should Know\" class=\"read-more\" href=\"https:\/\/itsupportwale.com\/blog\/10-javascript-best-practices-every-developer-should-know\/\" aria-label=\"Read more  on 10 JavaScript Best Practices Every Developer Should Know\">Read more<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-4764","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.0 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>10 JavaScript Best Practices Every Developer Should Know - ITSupportWale<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/itsupportwale.com\/blog\/10-javascript-best-practices-every-developer-should-know\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"10 JavaScript Best Practices Every Developer Should Know - ITSupportWale\" \/>\n<meta property=\"og:description\" content=\"It\u2019s 3:14 AM, the load balancer is throwing 504s like a malfunctioning pitching machine, and I\u2019ve found the culprit in a &#8220;clever&#8221; one-liner. 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