Blog

Thoughts on AI, software, and life. Short notes and long-form writing.

AWS VPC Networking Review: Subnet, Route Table, IGW, NAT, VPN, Direct Connect, Security Group, and NACL

A VPC is a private network space in AWS. EC2 instances run inside subnets, and subnets belong to a VPC.

Big DataMay 23, 2026

Big Data Review: Hadoop, Spark, and Hive

Big data systems solve a basic problem: data is too large for one machine to store or process efficiently, so storage and computation must be distributed.

DatabaseMay 23, 2026

Database Review: SQL, Normalization, NoSQL, and Common Database Types

DatabaseSQLNoSQL

Database design starts with relationships, query patterns, and scaling needs.

DevOpsMay 23, 2026

Git, GitHub Actions, Shell, and Docker: From Local Development to CI/CD and Containers

GitHub ActionsDockerfileDocker Compose+1

These tools solve delivery problems: collaboration, automated testing, packaging, runtime consistency, and deployment.

Software EngineeringMay 23, 2026

NAS, OA Systems, Public File Notices, and Access Control

NASOA SystemAccess Control+1

This topic is about internal information systems: where files live, how workflows move, and how permissions are controlled.