sqlew

What DeNA's Perl-to-Go Migration Reveals About the Value of Code-Independent Design Records

Migrating a 6,000-line legacy Perl API to Go, powered by AI agents. A case study published on DeNA's engineering blog paints a vivid picture of both the promise…

Decision and Constraint: How sqlew's Dual Records Transform AI Reasoning Patterns

Recent research suggests that ADR (Architecture Decision Record) can dramatically improve the reasoning efficiency of coding agents. But in traditional ADR, two…

Why AI Ignores Your "Use TDD" Instruction: The Compliance Gap Between Instruction and Rationale

You wrote "Use TDD" in CLAUDE.md, but the AI doesn't write tests. Or it writes them, but they're clearly going through the motions. If you've tried pr…

Recording Design Intent for AI Efficiency: What Measured Data Shows About the Power of "Why"

Write a function that returns a string. Give this instruction to an AI coding tool, and the implementation you get back varies wildly depending on context. In C…

The First Wall You Hit When Maintaining Legacy Code with AI

You want to use AI coding to streamline legacy code maintenance. You point the AI agent at the codebase, and immediately hit a wall. "Why is it implemented…