SOLID: Build Code Like Perfect LEGO Bricks

Tue, 04 Aug 2026 05:42:51 +0900

🔍 What Is It?

SOLID is five rules that help programmers write code that is easy to fix, add to, and change without breaking everything else.

Imagine you built a giant LEGO castle where every piece was glued to every other piece. Change one brick and the whole thing collapses. SOLID is a set of five rules that programmers follow so their code snaps together cleanly — easy to fix, easy to grow, and nothing falls apart when you make a change. Each letter stands for one rule. S means each piece of code should do exactly one job. O means you can add new features without rewriting the old ones. L means you can swap one similar part for another and everything still works. I means each part only knows what it needs to know. D means the big parts of your program should not depend directly on tiny details — both should follow a shared plan. Grown-ups use SOLID because software that ignores these rules turns into a tangled mess over time. A small fix in one place breaks five other things. SOLID keeps a whole team’s code clean and organized so they can work on it for years without chaos.

Solid on Framework Made Simple

SOLID: Build Code Like Perfect LEGO Bricks

🔍 What Is It?