Project scaffolding in NestJS - Performance & Optimization

Performance: Project scaffolding

MEDIUM IMPACT

Project scaffolding affects initial load speed and bundle size by determining the structure and included modules of the NestJS app.

Setting up a new NestJS project with optimal performance

NestJS

nest new my-app --skip-install
// Remove unused modules and providers before installing dependencies
// Use minimal modules and lazy load features where possible

Reduces bundle size and speeds up app bootstrap by including only needed code.

📈 Performance GainSaves 50+ KB in bundle, reduces initial load blocking by 100ms

Setting up a new NestJS project with optimal performance

NestJS

nest new my-app
// Accept all default modules including unnecessary ones like testing and example modules
// Add many unused providers and controllers manually after scaffolding

Includes unnecessary modules and code increasing bundle size and startup time.

📉 Performance CostAdds 100+ KB to initial bundle, blocks rendering for 200ms longer

Performance Comparison

Pattern	DOM Operations	Reflows	Paint Cost	Verdict
Default scaffold with all modules	N/A	N/A	High due to large JS bundle	[X] Bad
Minimal scaffold with only needed modules	N/A	N/A	Lower due to smaller JS bundle	[OK] Good

Rendering Pipeline

Project scaffolding defines the initial code structure and modules loaded, which affects the JavaScript bundle size and how fast the browser can parse and execute the app code.

→Network

→Script Parsing

→Script Execution

→First Contentful Paint

⚠️ BottleneckScript Execution due to large bundles from unnecessary modules

Core Web Vital Affected

LCP

Project scaffolding affects initial load speed and bundle size by determining the structure and included modules of the NestJS app.

Optimization Tips

1Keep your NestJS scaffold minimal to reduce initial bundle size.

2Remove unused modules and providers before installing dependencies.

3Use lazy loading for features to improve startup performance.

Performance Quiz - 3 Questions

How does including many unused modules in NestJS scaffolding affect performance?

A Improves startup speed by preloading features

B Has no effect on performance

C Increases bundle size and slows initial load

D Reduces memory usage

DevTools: Performance

How to check: Record page load and look at the scripting time and first contentful paint timing.

What to look for: Long scripting times and delayed first contentful paint indicate heavy initial bundles from scaffolding.