DRF installation and setup in Django - Performance & Optimization

Performance: DRF installation and setup

MEDIUM IMPACT

This affects the initial page load speed and backend response time by adding the Django REST Framework to the project.

Setting up Django REST Framework for API development

Django

pip install djangorestframework==3.14.0
INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'rest_framework',
    # other apps
]
REST_FRAMEWORK = {
    'DEFAULT_PAGINATION_CLASS': 'rest_framework.pagination.LimitOffsetPagination',
    'PAGE_SIZE': 10,
    'DEFAULT_THROTTLE_CLASSES': ['rest_framework.throttling.UserRateThrottle'],
    'DEFAULT_THROTTLE_RATES': {'user': '1000/day'},
    'DEFAULT_RENDERER_CLASSES': ['rest_framework.renderers.JSONRenderer'],
    'DEFAULT_PARSER_CLASSES': ['rest_framework.parsers.JSONParser']
}

Pinning DRF version ensures stable dependencies; configuring pagination and throttling reduces server load and response time; limiting renderers and parsers reduces processing overhead.

📈 Performance Gainreduces response time by 30-50ms, lowers memory usage, and avoids unnecessary processing

Setting up Django REST Framework for API development

Django

pip install djangorestframework
# Adding 'rest_framework' to INSTALLED_APPS without version pinning or minimal setup
INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'rest_framework',
    # other apps
]
# No configuration for pagination, throttling, or caching

Installing DRF without version control and without configuring performance-related settings can lead to larger package size and slower API responses.

📉 Performance Costadds ~1MB to backend dependencies, increases response time by 50-100ms due to default settings

Performance Comparison

Pattern	Backend Dependency Size	Response Time Impact	Memory Usage	Verdict
Unpinned DRF with default settings	~1MB added	Adds 50-100ms	Higher memory usage	[X] Bad
Pinned DRF with optimized settings	~1MB added	Adds 20-50ms	Lower memory usage	[OK] Good

Rendering Pipeline

DRF setup affects the backend processing stage before the browser receives data. It influences how fast the API can respond with JSON data, impacting the time until the browser can render content.

→Backend Processing

→Network Transfer

→Browser Rendering

⚠️ BottleneckBackend Processing due to serialization and view handling

Core Web Vital Affected

LCP

This affects the initial page load speed and backend response time by adding the Django REST Framework to the project.

Optimization Tips

1Always pin DRF version to avoid unexpected performance issues.

2Enable pagination to limit data size per API response.

3Use throttling and limit renderers to reduce backend load.

Performance Quiz - 3 Questions

How does pinning the DRF version in requirements affect performance?

A It increases the package size significantly.

B It ensures stable dependencies and avoids unexpected slowdowns.

C It disables pagination by default.

D It automatically caches all API responses.

DevTools: Network

How to check: Open DevTools, go to Network tab, filter API calls, and check the timing breakdown for backend response time.

What to look for: Look for the 'Waiting (TTFB)' time to see backend processing delay; lower times indicate better DRF setup.