Optimizing NPM Build EC2

### 1. **Instance Type and Resources**:
– **Free Tier Limitations**: AWS Free Tier instances (such as `t2.micro`) have limited CPU and memory resources, which can affect the performance of processes like `npm run build`. Consider upgrading to a more powerful instance type (like `t3.micro`, `t3a.micro`, or higher) to get better performance.
– **Check System Resources**: Monitor your instance's CPU, memory, and disk usage during the build process using `top`, `htop`, or AWS CloudWatch to see if it's maxing out resources.

### 2. **Disk Speed**:
– **EBS Optimization**: EC2 Free Tier instances come with general-purpose SSD (gp2) EBS volumes. If you're experiencing slow disk I/O during builds, consider moving to a provisioned IOPS (io1) volume, or ensure your `node_modules` directory is on an optimized disk.

### 3. **Caching Dependencies**:
– **Leverage Caching**: Use `npm ci` instead of `npm install` to speed up dependency installation by leveraging an existing lockfile (`package-lock.json`). You can also consider caching the `node_modules` directory to avoid reinstalling dependencies each time.
– **Docker Cache**: If you're using Docker, ensure that you are caching layers properly. You can cache `node_modules` in your Dockerfile using the `–mount=type=cache` option.

### 4. **Optimize the Build Process**:
– **Reduce Build Complexity**: Review the `webpack.config.js` or other build configurations to minimize the size of assets, split bundles, and use other performance optimization techniques such as tree shaking, minification, and lazy loading.
– **Disable Source Maps**: If you're generating source maps, try disabling them during the production build (`devtool: false` in your Webpack config).
– **Parallel Execution**: Some build tools (like Webpack) support parallel builds. If using Webpack, enable multi-threaded or parallel mode using plugins like `thread-loader`.

### 5. **Use a CI/CD Pipeline**:
– **Offload Build Process**: You can consider using a CI/CD pipeline (such as GitHub Actions, GitLab CI, or AWS CodeBuild) to offload the build process to more powerful cloud instances, reducing the load on your Free Tier EC2 instance.

### 6. **Use a CDN for Assets**:
– If you're building a web app, ensure that static assets like images, fonts, and CSS are being served from a CDN to offload traffic from your EC2 instance.

### 7. **Profile the Build**:
– **Webpack Bundle Analyzer**: If you are using Webpack, use a bundle analyzer (`webpack-bundle-analyzer`) to find any performance bottlenecks or oversized dependencies that may be slowing down your build.

By applying some of these strategies, you should be able to see improvements in your build times. If possible, consider testing with a more powerful EC2 instance for the build process.

### 1. **Optimize Dependencies**:
Use Vite's `optimizeDeps` option to pre-bundle dependencies. This will help with faster subsequent builds.

// vite.config.js
export default {
  optimizeDeps: {
    include: ['vue', 'other-dependency'], // Add the most commonly used dependencies here
    exclude: ['some-large-dependency'], // Exclude any large dependencies if not needed for every build
  }
}

### 2. **Enable Cache for Faster Builds**:
Vite uses caching to avoid redundant work. Ensure that `cacheDir` is set and not being wiped during each build.

// vite.config.js
export default {
  cacheDir: './node_modules/.vite', // Customize the cache directory location if needed
}

### 3. **Split Code for Faster Load**:
Enable code splitting to improve performance by only loading necessary chunks on demand.

// vite.config.js
export default {
  build: {
    chunkSizeWarningLimit: 1000, // Increase chunk size limit to avoid unnecessary warnings
    rollupOptions: {
      output: {
        manualChunks: (id) => {
          if (id.includes('node_modules')) {
            return 'vendor'; // Split vendor code into a separate chunk
          }
        },
      },
    },
  },
}

### 4. **Use `esbuild` for Minification**:
Vite uses `esbuild` by default for minification, which is very fast. You can adjust minification settings or disable it in certain cases if you prefer faster builds during development.

// vite.config.js
export default {
  build: {
    minify: 'esbuild', // Default minification using esbuild
    sourcemap: false, // Disable sourcemaps for faster builds
  },
}

### 5. **Disable Source Maps (in production)**:
Source maps can slow down the build process. Disabling them can improve build performance, especially in production.

// vite.config.js
export default {
  build: {
    sourcemap: false, // Disable source maps for faster production build
  },
}

### 6. **Use `build.target` for Faster Builds**:
Specifying a build target can help Vite optimize the build process for modern browsers.

// vite.config.js
export default {
  build: {
    target: 'esnext', // Target the latest browsers for faster builds
  },
}

### 7. **Enable Parallel Processing**:
If you're using `esbuild`, it runs in parallel, but Vite doesn’t parallelize build tasks by default. To take advantage of multiple cores, you can use the `thread-loader` or a plugin that enables parallelization.

// vite.config.js
import { defineConfig } from 'vite'
import vue from '@vitejs/plugin-vue'

export default defineConfig({
  plugins: [vue()],
  build: {
    target: 'esnext',
    minify: 'esbuild',
    outDir: 'dist',
    chunkSizeWarningLimit: 2000,
  },
})

### 8. **Limit Plugin Usage**:
Plugins can significantly slow down Vite builds, so only use the essential ones. Remove any unnecessary or inefficient plugins, and ensure you're using up-to-date versions.

### 9. **Use SSR for Production** (Optional):
If you're building a static site or need server-side rendering (SSR), you can adjust Vite to optimize SSR builds.

// vite.config.js
export default {
  ssr: {
    noExternal: ['vue', 'some-other-package'], // Pre-bundle specific libraries for SSR
  },
}

### Example `vite.config.js` Optimizations:

import { defineConfig } from 'vite'
import vue from '@vitejs/plugin-vue'

export default defineConfig({
  plugins: [vue()],
  optimizeDeps: {
    include: ['vue', 'axios'], // Pre-bundle dependencies to speed up dev builds
  },
  build: {
    chunkSizeWarningLimit: 1000, // Avoid warnings on chunk size
    minify: 'esbuild', // Use esbuild for minification
    sourcemap: false, // Disable source maps for production build
    target: 'esnext', // Optimize for the latest browsers
    outDir: 'dist', // Output directory
    rollupOptions: {
      output: {
        manualChunks: (id) => {
          if (id.includes('node_modules')) {
            return 'vendor'; // Separate vendor code into its own chunk
          }
        },
      },
    },
  },
  cacheDir: './node_modules/.vite', // Ensure the cache directory is properly configured
})

### Conclusion:
By applying these optimizations, you can significantly speed up the build process in Vite, especially on resource-constrained environments like AWS Free Tier instances. You may also want to experiment with different settings based on your project's specific needs (e.g., using different build targets or tweaking `chunkSizeWarningLimit`).