In-depth breakdowns of how real systems are built: the components, the trade-offs, and why they were designed the way they were.
Each post covers a complete system or subsystem. The goal is not just to describe what exists, but to explain the reasoning behind the design decisions.
Mainframe
- Architecture: Mainframe
The hardware, software, and operational model behind the systems still running the world's most critical workloads. - Architecture: CICS
How IBM's transaction processing system manages thousands of concurrent short-lived transactions on z/OS. - Architecture: VSAM
The file organization and access method that underpins most mainframe data storage. - Architecture: DB2 on z/OS
How IBM's relational database is structured and tuned for the mainframe environment. - Architecture: JES and Batch Processing
How z/OS manages the submission, scheduling, and execution of batch jobs at scale. - Architecture: CICS Web Services
How CICS exposes existing COBOL programs as SOAP web services, bridging mainframe logic and modern consumers.
Messaging and Streaming
- Architecture: Kafka
Brokers, partitions, consumer groups, replication, and how Kafka moves data reliably at scale. - Architecture: Kafka Active-Active with Confluent Bidirectional Cluster Linking
How to run two Kafka clusters simultaneously under live traffic with automatic failover and no manual promotion step.
Kubernetes and Cloud Infrastructure
- Architecture: Kubernetes
Control plane, worker nodes, pods, services, ingress, autoscaling, and how all the pieces fit together. - Architecture: Coder
How Coder moves development off local machines onto cloud infrastructure, and what that means for team consistency and security.
Security and Networking
- Architecture: Zscaler
How Zscaler intercepts, inspects, and routes traffic as a cloud-native security proxy, and what that means for developers day to day.
Enterprise Architecture
Part of the Enterprise Architecture series, which follows one fictional bank across eleven posts.
- Architecture: TOGAF and the ADM
The framework most people mean by "enterprise architecture," and the Architecture Development Method that drives it from vision to governed implementation. - Architecture: The Application Portfolio
Treating the whole software estate as a managed portfolio: the TIME model, rationalizing duplicate systems, and technical debt as a portfolio property.
Posts are added to this page as they are published. If you are new to the series, Architecture: Kubernetes is a good entry point for cloud-native systems, and Architecture: Mainframe is the place to start for the mainframe track.
Written by Phee Jay.