Certificate chain differences affect TLS handshake time:

# Testing handshake speed with openssl
openssl s_time -connect example.com:443 -new -cipher ECDHE-RSA-AES128-GCM-SHA256
# Compare results between LE and paid certs

• EV certificates for financial institutions
• Extended validation for e-commerce
• Legacy system compatibility (e.g., Windows XP)
• Enterprise warranty requirements

Using AWS ACM with Let's Encrypt for different services:

# Terraform configuration for hybrid SSL setup
resource "aws_acm_certificate" "main" {
  domain_name       = "example.com"
  validation_method = "DNS"
  lifecycle {
    create_before_destroy = true
  }
}

resource "aws_lb_listener" "frontend" {
  load_balancer_arn = aws_lb.frontend.arn
  certificate_arn   = aws_acm_certificate.main.arn
}

resource "null_resource" "letsencrypt_backend" {
  provisioner "local-exec" {
    command = "certbot certonly --standalone -d api.example.com"
  }
}

SSL/TLS certificates are essential for securing web applications, but developers often face a choice: free certificates from Let's Encrypt or paid alternatives like AWS Certificate Manager (ACM). This article explores the technical differences, use cases, and trade-offs.

Let's Encrypt provides Domain Validation (DV) certificates only, while paid services offer:

• Organization Validation (OV)
• Extended Validation (EV)

Example of checking certificate details in Node.js:

const https = require('https');
const tls = require('tls');

const options = {
  host: 'example.com',
  port: 443,
  method: 'GET'
};

const req = https.request(options, (res) => {
  const cert = res.socket.getPeerCertificate();
  console.log('Certificate details:', {
    subject: cert.subject,
    issuer: cert.issuer,
    validFrom: cert.valid_from,
    validTo: cert.valid_to,
    serialNumber: cert.serialNumber
  });
});

req.end();

Let's Encrypt certificates expire every 90 days, requiring automation:

# Sample certbot renewal script
#!/bin/bash
certbot renew --pre-hook "systemctl stop nginx" \
              --post-hook "systemctl start nginx" \
              --quiet

Paid certificates typically last 1-2 years, reducing maintenance overhead.

Both options support wildcards, but implementation differs:

# Let's Encrypt wildcard request
certbot certonly --manual --preferred-challenges=dns \
                -d *.example.com -d example.com

# AWS ACM wildcard via CLI
aws acm request-certificate --domain-name *.example.com \
                          --validation-method DNS

AWS ACM offers deeper integration with AWS services:

# CloudFormation snippet for ACM with ALB
Resources:
  MyALB:
    Type: AWS::ElasticLoadBalancingV2::LoadBalancer
    Properties:
      Listeners:
        - Protocol: HTTPS
          Port: 443
          Certificates:
            - CertificateArn: !Ref MyCertificate

Choose Let's Encrypt when:

• You need simple DV certificates
• You can automate renewals
• Budget is constrained

Consider paid certificates when:

• You need OV/EV validation
• Managing renewals is problematic
• Using cloud services with native integration
• Require immediate revocation