Short, clear write-ups on protocols, tools, and concepts. Each post takes one idea and explains it properly: what problem it solves, how it works, and where you will encounter it in the real world.
Posts are grouped by topic. No prior knowledge of the specific subject is assumed — just a working background as an engineer.
Networking
- Explained: STUN Protocol
How peers behind NAT discover each other before a WebRTC call connects. - Explained: NAT
Why private IPs work on the internet and how routers translate addresses. - Explained: DERP Protocol
A relay that forwards encrypted packets when a direct peer connection is not possible. - Explained: IPSec VPN Tunnels
How IPSec negotiates, wraps, and protects packets at every hop. - Explained: Webhooks
How apps push real-time data updates without polling, and best practices for doing it securely. - Explained: MQTT
The lightweight pub/sub protocol behind most IoT communication, covering architecture and use cases.
Kubernetes
- Explained: Node Affinity
Controlling which nodes a pod can and cannot be scheduled onto. - Explained: Taints and Tolerations
Preventing pods from landing on the wrong nodes, and granting exceptions when you need them.
Distributed Systems
- Explained: Gossip Protocol
How nodes in a cluster spread information to each other without a central coordinator. - Explained: Bloom Filters
A probabilistic data structure that answers "have we seen this?" using very little memory. - Explained: Bastion Server
A single hardened entry point that keeps your private infrastructure off the public internet. - Explained: Distributed Storage Systems
Architecture, replication, and consistency models behind scalable distributed storage.
Messaging and Streaming
- Explained: Kafka vs AMQP
How the two messaging models differ in architecture, and when to reach for each one.
Data and Architecture
- Explained: Data Warehouse, Lake and Lakehouse
The differences between the main data storage paradigms and how to choose between them. - Explained: Lambda Architecture
A data-processing pattern that combines batch and real-time layers to handle large-scale streams. - Explained: Data Mesh
A decentralized approach to data ownership where domain teams manage their own data as a product.
Mainframe
- Explained: COBOL
The language that still runs the world's most critical transactions, and why it has lasted this long. - Explained: JCL
How batch jobs are defined, submitted, and controlled on z/OS using Job Control Language. - Explained: RACF
The security and access control system that protects z/OS resources at every level.
Tooling
- Explained: WSL (Windows Subsystem for Linux)
How Microsoft built native Linux binary support into Windows, without a VM or dual boot. - Explained: WebDrivers
How Selenium's WebDrivers interact with browsers to automate testing at the protocol level.
Posts are added to this page as they are published. If you are looking for a place to start, Explained: NAT is a good entry point.
Written by Phee Jay.