SDN, eBPF, and the Programmability Pattern

What do your VPC, your kernel, and your Kubernetes cluster have in common?

They're all part of the same trend: making previously fixed infrastructure programmable.

• Cloud made infrastructure programmable.
• SDN made networking programmable.
• eBPF is making operating system capabilities programmable.

I didn't see this connection until recently. I've deployed applications on AWS — Lambda functions, API Gateways, VPCs, security groups. Written Terraform and Terragrunt configs to spin it all up.

But I was using these services like a remote control — I knew which buttons to press, not how the TV worked. That felt like a gap worth closing.

SDN — the network becomes software

Every VPC you've ever created? That's SDN. Every security group rule, every route table — software pretending to be hardware.

Instead of configuring devices one by one, each with its own brain, SDN centralizes control. One brain. Every device follows instructions.

eBPF — the kernel becomes programmable

A similar shift is happening inside the operating system itself.

eBPF lets you run tiny programs inside the Linux kernel — without modifying it. Think of it as whispering instructions to the engine while the car is still moving.

Kubernetes networking uses it. Observability tools use it. Security tools use it. It's quietly powering half the infrastructure we take for granted.

The pattern underneath both

Different problems. Similar philosophy.

Sometimes learning a new technology isn't about the technology itself. It's about recognizing the bigger trend it belongs to.