What are Route 53 and CloudFront?

Question

Accepted Answer

**Route 53** is AWS's **DNS** service (translating domain names to addresses, with routing policies); **CloudFront** is AWS's **CDN** (Content Delivery Network, caching content at edge locations worldwide for fast delivery). Both improve performance and availability for web applications.

## Route 53 — DNS and traffic routing

```text
Route 53 is a managed DNS service (+ domain registration):
  → translates domain names (example.com) → IP addresses / AWS resources
  → ROUTING POLICIES (intelligent traffic direction):
    - SIMPLE → one destination
    - WEIGHTED → split traffic by percentage (e.g. A/B testing, gradual rollout)
    - LATENCY → route users to the lowest-latency region (performance)
    - GEOLOCATION → route by user location
    - FAILOVER → route to a backup if the primary fails (HIGH AVAILABILITY)
  → HEALTH CHECKS → route away from unhealthy endpoints
```

## CloudFront — CDN (content delivery)

```text
CloudFront is a Content Delivery Network — caches content at EDGE locations worldwide:
  → content served from an edge location NEAR the user → low latency, fast loads
  → caches static assets (images, CSS, JS, videos) close to users globally
  → reduces load on your origin (S3, EC2, ALB) — the edge serves cached content
  → also: DDoS protection, HTTPS, can serve dynamic content too
→ User → nearest CloudFront EDGE (cached?) → if miss, fetch from ORIGIN, then cache
```

## Used together

```text
Route 53 (DNS) → points your domain at CloudFront (CDN) → which serves cached content
  from edges and fetches from origins (S3/ALB) on misses.
→ Common pattern for fast, global, highly-available web delivery.
```

## Why it matters

Understanding Route 53 and CloudFront is valuable because they're important services for **web application performance and availability**, so it's useful AWS knowledge. **Route 53** (DNS) is more than basic name resolution — its **routing policies** enable sophisticated traffic management: **latency-based routing** (directing users to the lowest-latency region for performance), **weighted routing** (splitting traffic for A/B testing or gradual rollouts), **failover routing** (directing to a backup if the primary fails, supporting **high availability**), and **geolocation routing** — combined with health checks that route away from unhealthy endpoints.

This makes Route 53 a tool for both performance (routing users optimally) and reliability (failover). **CloudFront** (CDN) improves **performance** by caching content at **edge locations worldwide**, so content is served from a location near each user (reducing latency and speeding page loads globally) while also **reducing load on origin servers** (the edge serves cached content) and providing benefits like DDoS protection and HTTPS — important for delivering fast experiences to a global audience.

Understanding how they're **used together** (Route 53 pointing the domain at CloudFront, which serves cached content from edges and fetches from origins like S3 or ALB on misses) reflects the common pattern for fast, global, highly-available web delivery.

Since web application performance (latency, global delivery) and availability (failover, optimal routing) are important concerns, and since Route 53 (intelligent DNS routing) and CloudFront (global content caching) are AWS's key services for them, understanding Route 53 and CloudFront is valuable, practically-relevant AWS knowledge for delivering performant, available web applications — useful services for improving user experience globally and building resilient, fast web delivery, important for anyone architecting customer-facing AWS applications.