AWS IoT Core vs Overengineered Messaging Systems

It's surprisingly common. A team builds a custom messaging layer… on top of AWS — when AWS IoT Core already solves most of the problem.

Why this happens

Usually, it comes from one of three places:

• Engineers default to what they know (Kafka, MQTT brokers, etc.)
• Teams don't fully understand AWS IoT Core capabilities
• There's a fear of vendor lock-in

So instead of using native services, they build around them.

What AWS IoT Core already gives you

Out of the box, AWS IoT Core provides:

• Secure MQTT messaging
• Device authentication (cert-based)
• Scalable ingestion
• Rules engine for routing data
• Integration with AWS services

For many use cases, that's enough.

Where overengineering creeps in

You'll often see:

• Custom brokers duplicating IoT Core
• Extra queues and services adding latency
• Complex routing logic that's hard to maintain
• Security handled inconsistently across layers

The result? More moving parts. More risk.

When custom architecture does make sense

There are valid reasons:

• Multi-cloud requirements
• Highly specialised routing logic
• Extreme throughput edge cases
• Regulatory constraints

But these are exceptions — not the default.

The practical approach

Start simple:

• Use AWS IoT Core as the backbone
• Add complexity only when proven necessary
• Validate performance and cost before expanding

Final thought

Most AWS IoT platforms don't fail because they're too simple. They fail because they became too complicated too early.