Write Your Own Build Scripts

JavaScript's build tooling has evolved through at least five major generations: Grunt, Gulp, Webpack, Rollup, Parcel, Vite, esbuild, Turbopack. Each promised to solve the problems of the last. Each introduced new complexity. Meanwhile, a 50-line shell script still does the job for most projects.

The cognitive burden of choosing and configuring build tools has become a significant overhead. A developer starting a new project faces analysis paralysis: which bundler, which transpiler, which package manager, which testing framework? Each choice implies tradeoffs that may not become apparent until months into development.

I've watched this cycle repeat for decades. The tools change, the pattern doesn't. And increasingly, I find myself reaching for something simpler.

The Configuration Fatigue Problem

Webpack's configurability is both its strength and its curse. As MIT Technology Review notes, the flexibility to customize every aspect of the build process often leads to "configuration fatigue," where developers spend more time tweaking Webpack than writing application code. Tools like webpack-merge or webpack-chain help, but they add yet another layer of complexity.

This isn't a Webpack-specific problem. Every sophisticated build tool eventually develops its own ecosystem of plugins, loaders, and configuration patterns. Understanding not just your code but the build system's opinion about how code should be structured becomes necessary.

The latest generation of tools like Vite attempts to eliminate configuration through intelligent defaults. That's progress. But it's still a black box you don't control. When it works, it's magic. When it breaks, you're debugging someone else's abstractions. I've written about this before with the layer tax: every abstraction costs something.

What Build Tools Actually Do

Strip away the marketing, and most JavaScript build tools do a handful of things:

Bundling. Combining multiple files into fewer files for efficient loading. This matters less now that HTTP/2 handles multiple requests efficiently and ES modules work natively in browsers.

Transpiling. Converting modern JavaScript to older syntax for browser compatibility. Increasingly unnecessary as browser support improves and you can target evergreen browsers.

Minification. Removing whitespace and shortening variable names. A single command-line tool does this.

Asset processing. Optimizing images, processing CSS, generating sourcemaps. Each of these is a discrete task that can be handled by dedicated tools.

The complexity comes from orchestrating these tasks and managing dependencies between them. But that orchestration doesn't require a framework. A shell script can do it.

The Shell Script Alternative

Here's what a simple build script looks like:

#!/bin/bash
# Build script - does exactly what it says

# Clean
rm -rf dist/

# Copy static assets
cp -r public/* dist/

# Bundle JavaScript (using esbuild for speed)
esbuild src/index.js --bundle --minify --outfile=dist/app.js

# Process CSS
postcss src/styles.css -o dist/styles.css

# Done
echo "Build complete"

That's it. No configuration files. No plugin ecosystem. No version conflicts. No mysterious errors from deep in a dependency tree. Just commands that do what they say.

When something breaks, you know exactly where to look. When you need to change something, you edit one file. When a new developer joins, they can read the entire build process in 30 seconds.

Understanding What You Ship

There's a deeper benefit to writing your own build scripts: you understand what you're shipping.

With complex build tools, the output is often a mystery. Files appear in your dist folder, transformed through layers of plugins and loaders. You trust that the output is correct because the tool is popular, not because you've verified it.

With a simple script, every transformation is explicit. You can inspect each step. You know exactly what code runs in production because you defined every transformation yourself.

This matters more than it used to. As comprehension debt becomes a real concern with AI-generated code, understanding your entire pipeline becomes a competitive advantage. You can't debug what you don't understand.

When You Actually Need Build Tools

I'm not saying build tools are never appropriate. They solve real problems:

Hot module replacement. If you're building a complex UI and need instant feedback, Vite's dev server is genuinely better than anything you'd build yourself.

Code splitting. Automatic chunking for large applications requires dependency analysis that build tools do well.

Tree shaking. Removing unused code from dependencies is complex to implement correctly.

Framework integration. If you're using React, Vue, or Svelte, their ecosystems assume specific build tools. Fighting that assumption costs more than it saves.

The question is whether you need these features. For a marketing site, a blog, an internal tool, or an API? Probably not. The simple approach is often sufficient.

The Performance Argument

Modern build tools compete on speed. According to Kinsta's benchmarks, esbuild is 10-100x faster than Webpack. Vite's dev server starts in milliseconds instead of seconds. Turbopack promises even more.

But here's the thing: a simple shell script is also fast. When you're running four commands sequentially, build time is measured in seconds regardless of the tool. The performance gains from Go-based or Rust-based bundlers matter at scale. For most projects, any approach is fast enough.

I've seen teams spend days optimizing Webpack builds that a shell script would have completed in two seconds. The meta-work of configuring the build system takes longer than the build itself.

Learning What Matters

Writing your own build scripts teaches you what build tools actually do. That understanding makes you better at using build tools when you need them.

If you've never concatenated files manually, you don't really understand bundling. If you've never run Terser directly, you don't understand minification. If you've never written a file watcher, you don't understand how hot reload works.

This is similar to how understanding SQL makes you better at using ORMs. The abstraction serves you better when you know what it's abstracting.

The industry has collective cargo-culted its way into complex toolchains whether or not they're appropriate. The result is developers who can configure Webpack but can't explain what a bundler does.

A Practical Approach

My recommendation:

Start with the simplest thing that works. A shell script calling command-line tools. Add complexity only when you've proven you need it.

Understand each tool you add. If you can't explain what a tool does and why you need it, you probably don't need it.

Measure before optimizing. Is your build actually slow? Or are you optimizing because the industry says you should?

Consider maintenance burden. A 50-line script you understand is easier to maintain than a configuration file you copied from Stack Overflow.

The goal isn't to avoid all build tools. It's to choose them consciously, understanding what you're trading for what you're getting.

Build Complexity Audit

Do you actually need sophisticated build tooling, or would a shell script suffice?

"Each promised to solve the problems of the last. Each introduced new complexity. Meanwhile, a 50-line shell script still does the job for most projects."