Route 53 (DNS)

Let's think about this for a second

DNS is the system that translates a domain name (human-readable, e.g. example.com) into an IP address (computer-readable, e.g. 54.123.45.67) — Route 53 is AWS's DNS service, covering everything from domain registration to DNS record management, health checks, and traffic routing policies (latency-based, geolocation-based). The most commonly used record types are A Record (domain → IPv4 address), CNAME (domain → another domain name), and Alias Record (connects directly to an AWS resource like ALB/CloudFront/S3, at no extra cost).

Let's connect this to a real scenario

If you want to point `app.thutatech.com` at an EC2 instance's Elastic IP, you create an A Record — but if you're pointing it at an ALB, you should use an Alias Record instead (since an ALB's IP can change, an Alias Record tracks it automatically). If you have Health Check enabled, Route 53 can automatically route traffic to a backup server if a server goes down.

Route 53 = AWS's DNS service (domain registration + record management)
A Record = domain → IP address, CNAME = domain → domain, Alias Record = points to an AWS resource (ALB/S3/CloudFront)
Health Check = auto-routes to a backup if a server goes down

Let's look at this together

bash

# Create an A record pointing app.thutatech.com to an EC2 Elastic IP
aws route53 change-resource-record-sets \
  --hosted-zone-id Z123456789ABC \
  --change-batch '{
    "Changes": [{
      "Action": "CREATE",
      "ResourceRecordSet": {
        "Name": "app.thutatech.com",
        "Type": "A",
        "TTL": 300,
        "ResourceRecords": [{"Value": "54.123.45.67"}]
      }
    }]
  }'

You should see

$ dig app.thutatech.com
;; ANSWER SECTION:
app.thutatech.com.  300  IN  A  54.123.45.67

Try it in 5 minutes

Read through the Route 53 documentation and write up, with examples, which scenarios call for an A Record versus an Alias Record (you only need to actually create one if you have your own domain).

A quick word of caution

When changing a domain's DNS while it's serving live production traffic, factor in the TTL/propagation time — a DNS change can take anywhere from a few minutes to a few hours to fully propagate worldwide.