10 Tips for Optimizing Node.js with Built-In Caching

Node.js is a powerful platform for building fast, scalable applications, especially for real-time and data-heavy operations. But with power comes responsibility. As your application grows, so do your performance concerns. One of the most efficient ways to solve performance bottlenecks without throwing more hardware at the problem is caching—and yes, Node.js has plenty of native and built-in techniques to help you do that.

If you're deploying your Node.js apps on platforms like Cloudways, you’ll also notice a big performance boost just by combining these caching techniques with a solid managed infrastructure. It's like adding turbo to your engine—optimized code on optimized hardware.

What is Caching (and Why It Matters in Node.js)?

Caching is the process of storing a copy of data in a temporary storage layer so future requests for that data can be served faster. Think of it like having a fast-access drawer for your most-used items rather than fetching them from the basement every time.

In Node.js, you often deal with I/O-bound operations—database queries, file system access, or external API calls. All of these can become bottlenecks. With caching, you reduce latency, cut down on repeated computation, and lower the load on your backend services.

1. Use In-Memory Caching with a JavaScript Object

For many use cases, the simplest and fastest cache is just… an object.

const cache = {};
 
function getFromCacheOrCompute(key, computeFn) {
  if (cache[key]) {
    return cache[key];
  }
 
  const result = computeFn();
  cache[key] = result;
  return result;
}

This is incredibly fast and perfect for short-lived data or read-heavy operations. But keep in mind:

It doesn’t persist across server restarts.
You’ll need to manage memory to avoid leaks.
It’s only available to a single Node.js process (not suitable for distributed apps).

For single-instance apps or functions like API token validation, settings lookup, or static configuration values, this approach works beautifully.

Tip: Use this for frequently accessed computed values that don't change often.

2. Use `require()` to Cache Modules Automatically

Did you know require() in Node.js caches the modules it loads?

const config = require('./config');

Every time you require the same file, Node.js serves it from the cache. This is great for:

Loading configuration files
Reusing utility libraries
Reducing startup time

If you want to bust the cache, you can delete it manually:

delete require.cache[require.resolve('./config')];

But in most cases, just let Node handle it.

Tip: Leverage require() caching when designing modules—break logic into reusable files.

3. Use `Map` for Predictable In-Memory Caching

While plain objects work, Map gives you more control and performance for dynamic keys.

const cacheMap = new Map();
 
function cacheData(key, data) {
  cacheMap.set(key, data);
}
 
function getCachedData(key) {
  return cacheMap.get(key);
}

Unlike plain objects:

Map preserves insertion order
It allows any type as keys (not just strings)
It has better performance for frequent additions/removals

You can also pair this with expiration logic or even TTL using timestamps.

Tip: Use Map when dealing with dynamic or frequent keys, like search queries or session info.

4. Add TTL Support to Your Cache

Sometimes, cached data shouldn’t live forever. Implementing TTL (Time-To-Live) is essential.

const cache = {};
 
function setWithTTL(key, value, ttlMs) {
  cache[key] = {
    value,
    expiresAt: Date.now() + ttlMs,
  };
}
 
function getWithTTL(key) {
  const entry = cache[key];
  if (!entry) return null;
  if (Date.now() > entry.expiresAt) {
    delete cache[key];
    return null;
  }
  return entry.value;
}

TTL helps ensure freshness, especially for data like:

API results
Auth tokens
Feature flags

Tip: Regularly sweep expired entries or use a background cleanup interval.

5. Memoize Expensive Functions

Memoization is a caching technique where you store the result of expensive function calls.

function memoize(fn) {
  const cache = new Map();
  return function (...args) {
    const key = JSON.stringify(args);
    if (cache.has(key)) return cache.get(key);
    const result = fn(...args);
    cache.set(key, result);
    return result;
  };
}

For functions like:

Complex math computations
String transformations
Parsing routines

Memoization can significantly reduce CPU usage.

Tip: Be mindful of cache size—use an LRU (Least Recently Used) policy if needed.

6. Cache Asynchronous Results

It’s common to have async operations like API requests or DB calls. Cache those too!

const cache = new Map();
 
async function fetchWithCache(key, fetchFn, ttl = 10000) {
  const now = Date.now();
  if (cache.has(key)) {
    const { value, expiresAt } = cache.get(key);
    if (now < expiresAt) return value;
  }
 
  const value = await fetchFn();
  cache.set(key, { value, expiresAt: now + ttl });
  return value;
}

Use this for:

Rate-limited APIs
Expensive DB joins
Auth provider metadata

Tip: This is especially useful in SSR (server-side rendering) and background job queues.

7. Cache Static Files in Memory

Serving static files? Instead of reading from disk on each request, cache them in memory.

const fs = require('fs');
 
const fileCache = new Map();
 
function getStaticFile(filePath) {
  if (fileCache.has(filePath)) {
    return fileCache.get(filePath);
  }
  const content = fs.readFileSync(filePath);
  fileCache.set(filePath, content);
  return content;
}

Combine this with a middleware for serving assets:

app.use('/assets', (req, res) => {
  const file = getStaticFile(`./public/${req.path}`);
  res.send(file);
});

Tip: Preload frequently requested files at startup to avoid delay on the first request.

8. Use Cluster and Shared Caching Wisely

If you're using Node.js clusters or worker threads, remember each worker has its own memory space. A cache created in one won't be available in another.

For shared caching:

Use external stores (like Redis or Memcached)
Or, in simpler cases, use IPC (inter-process communication) to sync

But for built-in solutions, use caching per worker and design accordingly.

Tip: If you're deploying to managed hosting (like Cloudways), their multi-core optimization handles this well, especially when combined with Redis or Memcached integration.

9. Serve Frequently Accessed JSON via Cache

Have a settings API or a frequently read config endpoint?

Cache the result of those file reads and serve the same parsed object to reduce file I/O.

let cachedConfig = null;
 
function getConfig() {
  if (cachedConfig) return cachedConfig;
  const raw = fs.readFileSync('./config.json', 'utf-8');
  cachedConfig = JSON.parse(raw);
  return cachedConfig;
}

This is much faster than re-parsing JSON on every call.

Tip: Bust the cache with a CLI command or API endpoint when updating config dynamically.

10. Combine Caching with Edge Deployment

This is where things get really exciting.

You’ve implemented caching in your Node.js app. Great. But now imagine combining that with edge-level caching through a platform like Cloudways, which offers CDN, Redis, and fast SSD hosting out of the box.

For example:

Cache HTML fragments at the edge
Cache API results in memory + Redis
Use cache-control headers to control frontend browser caching
Set up Varnish caching with minimal config

Even if your internal cache misses, Cloudways can serve the request lightning fast with its built-in layers—so the user never feels the delay.

Tip: Don’t just rely on in-app caching—deploy on an optimized platform where your cache can stretch from memory to edge to browser.

Bonus: When Not to Cache

Caching is powerful, but use it wisely. Avoid caching:

Sensitive or user-specific data without proper isolation
Rapidly changing values (like real-time counters)
Anything that must be 100% fresh (like stock prices or auction bids)

Caching stale or incorrect data is worse than no cache at all.

Final Thoughts

Caching is one of those secret weapons in every developer’s toolkit. In Node.js, you don’t even need fancy libraries to start seeing benefits—you can do a lot with native objects, Map, and thoughtful function design.

But when you combine that with a high-performance managed hosting platform like Cloudways, it’s a game-changer. You get the best of both worlds: efficient code and infrastructure designed for scale.

If you're serious about optimizing your app, deploy your next Node.js project on a platform that helps you scale with confidence—and watch your response times drop, user satisfaction rise, and server costs shrink.

Arunangshu Das @arunangshu_das