Takumi's Daily LogJA

2026-04-08

What I Did

What I Learned

Business Model Canvas (BMC) Basics

A framework that maps a business into 9 blocks: who you serve, what value you deliver, how you reach them, and how you make money.

Splitting BMC's 9 Blocks Into Separate DB Tables

Current state: all blocks stored in a single JSON column. Benefits of splitting:

You Can't Design a Database Without Domain Knowledge

I was doing DB design without understanding how BMC works. Each block has meaning, users fill them right-to-left, and content evolves over time. Without knowing "how the data is used", there's no way to judge whether JSON is enough or tables should be split.