CloudFront vs a Load Balancer: What Does Each One Do?

CloudFront delivers and optionally caches content at edge locations, while a load balancer distributes requests across healthy regional targets. Many production applications use both.

The right design depends on the workload, the failure the business must survive, the skills available to operate it, and the evidence the team can review. Start with those constraints before choosing services or copying a reference architecture.

The decision in practical terms

Area	Starting point	Why it matters
Edge	CloudFront	Terminates viewer requests near users and can cache eligible responses.
Origin	Load balancer	Routes regional traffic to healthy application targets.
Security	Layer controls	WAF, TLS, origin restrictions, and security groups protect different boundaries.
Decision	Often both	Use the CDN for edge delivery and the ALB for application routing.

These are starting points rather than universal rules. Validate them against production traffic, security boundaries, recovery objectives, team ownership, and the complete operating cost.

Recommended approach

1. Map the complete request path before selecting services.
2. Define cache behavior by URL and content type.
3. Restrict the origin so users cannot bypass edge controls.
4. Test health checks, failover behavior, logs, and invalidations.

Document the assumptions behind each decision. Give every production control an owner, verification method, and review date so the architecture does not silently drift away from its intended design.

Security, reliability, and cost checks

Use least-privilege access, temporary credentials for people and workloads, encryption where required, centralized operational evidence, and change approval proportional to risk. Confirm that backups can be restored and that alerts reach someone able to act.

Estimate the complete workload rather than one resource. Include data transfer, storage growth, logs, backup retention, security services, support, standby capacity, and engineering time. Review the estimate again after real usage becomes available.

Common mistakes

• Treating an ALB as a CDN.
• Caching personalized responses without a safe cache key.
• Leaving the origin publicly reachable without a reason.

Avoid solving an uncertain future problem by adding permanent complexity today. A simpler design with tested recovery, clear ownership, and observable behavior is usually safer than a sophisticated design nobody can operate confidently.

Continue planning

Use VPC explained and Load Balancer vs Auto Scaling for the next related decisions. The primary CloudSyncPK resource for this topic is AWS Network & Routing.

Verify with AWS

• How CloudFront delivers content
• Application Load Balancer introduction

The practical takeaway

CloudFront delivers and optionally caches content at edge locations, while a load balancer distributes requests across healthy regional targets. Many production applications use both. Confirm the choice with a small representative test, record the result, and revisit it when workload or business requirements change.