Nx - Caches Your Builds So You Don't Rebuild the Same Shit Twice

⚠️ Security Alert (August 2025): Before we talk features, know that Nx was hit by a major supply chain attack on August 26, 2025. Malicious versions leaked 2,349 GitHub tokens and other credentials. If you used Nx 21.5.0, 20.9.0, or several other versions published that week, assume compromise and rotate your credentials. The affected packages were removed, but this shows how quickly monorepo tooling can become an attack vector.

Nx solves a specific problem: when your monorepo builds take forever because you're rebuilding unchanged code. If your build times are fine, don't add this complexity to your life.

I learned this the hard way after spending a weekend trying to migrate a perfectly functional 3-project repo to Nx because I thought it would be "more professional." The build went from 2 minutes to 45 minutes of configuration debugging. Nx is overkill unless you have real build time pain.

The Problem Nx Actually Solves

Your shared library changes and suddenly you're rebuilding 47 projects that haven't changed at all. Your CI runs for an hour. Your developers hate their lives. Sound familiar?

Nx creates a dependency graph of your projects and runs tasks only for the stuff that actually changed. When you modify utils/math.ts, it figures out which apps use that library and skips everything else. The affected detection works about 90% of the time - the other 10% you'll be rebuilding everything anyway, but that's still a win.

The caching system stores task outputs based on inputs. Same inputs = cached results instead of re-execution. This applies to builds, tests, linting - anything reproducible. Our build times went from 45 minutes to 8 minutes after we got the cache configuration working.

New in Nx 21: Continuous tasks and the Terminal UI finally make running multiple dev servers bearable. You can now configure your frontend to depend on your backend, and Nx will start both automatically. The Terminal UI shows running tasks in one panel with logs in another - no more hunting through mixed output when three different servers are running.

Real World Gotchas You'll Hit

The Learning Curve Will Hurt: Plan for your team velocity to drop for 2-3 weeks while everyone figures out the new commands. nx affected:test instead of npm test trips people up constantly.

Configuration is a Pain in the Ass: The nx.json and project.json files have dozens of options. You'll spend time debugging why tasks aren't running or caching properly. The defaults are decent but you'll need to customize for your specific setup.

Windows Support Has Edge Cases: Most things work fine but you'll occasionally hit weird path issues or cache problems that Linux/Mac developers don't see. Not a dealbreaker but budget extra debugging time.

Affected Detection Isn't Perfect: Sometimes it misses dependencies or includes too much. You'll add manual override flags and gradually tune the dependency detection. It's not magic, just automated dependency analysis.

Language Support Reality Check

Started as a TypeScript/JavaScript tool and that's still where it shines. React, Angular, Node.js projects work great out of the box.

Other languages work through community plugins but expect more manual configuration:

• Go/Rust/Java: Possible but you're mostly writing custom task configurations
• .NET/Python: Community support varies, some plugins are maintained by one person
• Docker: Works fine for containerized builds

If you're not in the JavaScript ecosystem, evaluate carefully whether the complexity is worth it compared to simpler tools like Make or custom scripts.

The docs make it look easy. It's not. Budget a full day for setup and another week of tweaking before your team is productive. Here's what actually happens when you try to adopt Nx.

Installation Reality Check

Don't install globally: Despite what some guides say, npm install -g nx causes version conflicts. Use npx or install locally in your project.

## This will probably break something
npm install -g nx

## Do this instead
npx create-nx-workspace@latest myworkspace
## or add to existing project
npx nx@latest init

The nx init command is a liar: It claims to analyze your project structure and add Nx "without disrupting existing workflows." In reality, it's going to:

• Add 15+ configuration files to your repo
• Change how your package.json scripts work
• Break your existing CI/CD pipeline
• Require your team to learn new commands

It's not seamless. Plan accordingly.

Configuration Hell You'll Experience

The graph visualization is cool but useless: nx graph creates a pretty picture of your dependencies. Great for demos. In practice, you'll spend more time debugging why the graph is wrong than using it productively.

The Terminal UI is actually helpful: Nx 21 added a proper TUI that shows running tasks and logs separately. Navigate with arrow keys, press q to quit. It's the first Nx feature in years that actually improves daily workflow instead of adding complexity.

Task configuration will drive you insane: The nx.json and project.json files have hundreds of options. The defaults work for hello-world examples. Your real project needs custom input/output specifications, cache invalidation rules, and dependency overrides.

Expect error messages like:

✖ Cannot find project configuration for "my-app"
✖ Task "build" not found for project "my-lib"
✖ Circular dependency detected in project graph

Each one requires diving into documentation and Stack Overflow threads.

ESLint integration breaks everything: Nx has strong opinions about code organization and will enforce them through ESLint rules. Your existing code probably violates these rules. You'll spend time either:

1. Fixing hundreds of lint errors, or
2. Disabling the rules and wondering why you use Nx

The Learning Curve Hits Your Team Velocity

New commands confuse everyone: Instead of npm run test, it's now nx test my-app. Instead of npm run build, it's nx build my-app --configuration=production. Simple tasks now require remembering project names and configurations.

Affected commands don't work like you expect: nx affected:test should only run tests for changed projects. In practice:

• It misses dependencies and skips tests it should run
• It includes projects that haven't changed
• You'll end up running nx run-many --target=test --all anyway

Watch mode is flaky: nx serve and nx test --watch restart constantly, especially when files are shared between projects. You'll go back to running individual project commands directly.

The Stuff That Actually Works

Local caching saves time: Once configured properly, the cache does speed up rebuilds. Clean builds still take forever, but incremental changes are faster.

Project boundaries are useful: Nx can enforce architectural rules like "UI components can't import from backend libraries." This prevents spaghetti code in large teams.

Code generation is handy: nx generate @nx/react:component MyComponent creates properly structured components. The generators handle boilerplate and maintain consistency.

Migration Strategy That Won't Destroy Your Team

Start small: Pick one team's project for the initial migration. Don't try to convert your entire monorepo at once.

Expect a 2-3 week productivity drop: Your team will be slower while learning new workflows. Plan project timelines accordingly.

Designate an "Nx person": Someone needs to become the expert who maintains configurations and helps when things break. This isn't a "everyone learns it" situation.

Keep escape hatches: Don't delete your old build scripts immediately. You'll need fallbacks when Nx configurations break production deployments.