Claude Code Workflow: Stop Over-Engineering New Features

Writing a new service from scratch is often the biggest mistake a developer can make in a mature codebase. I recently went through a "post-mortem" of sorts with a project where we had two nearly identical services—one for "Wishlists" and one for "Favorites"—that were doing the exact same database operations. The result? A security patch was applied to one, but the other remained vulnerable for three months because the developer didn't search the codebase before starting.

The actual "bug" here isn't a syntax error; it's architectural redundancy. When you ignore existing patterns, you create a maintenance nightmare.

The "Search → Understand → Extend" Workflow

Instead of jumping straight into VS Code to create a new file, I've started adopting a strict pre-coding checklist to keep the codebase lean.

1. Search for Synonyms: If you're building a "Wishlist," don't just grep for that term. Search for favorite, saved, or bookmark. In a large LLM agent or complex AI workflow, the functionality you need often exists under a different name.
2. Understand the Implementation: Once you find a similar service, don't just copy-paste. You need to diagnose:
- Does it handle the logic (add/remove/check) as required?
- Is it protected by the correct auth middleware?
- Does the schema support the new data, or is it just "close enough"?
3. Extend, Don't Duplicate: If a service is 80% there, add a type column or a new parameter. It's significantly better to have one robust service than two fragile ones.

The Cost of "Clean Slate" Coding

When you build "fresh" without auditing the existing system, you end up with:

• Logic Drift: Two different ways to validate a user session.
• Maintenance Debt: Double the testing and double the documentation.
• Cognitive Load: New engineers have to learn two ways to do the same thing.

The goal should always be to write the minimum amount of new code necessary to solve the problem. If you can solve a ticket by adding one column to an existing table and three lines of logic to an existing service, that is a senior-level win.

Search 
  ↓
Understand 
  ↓
Extend

The most efficient deployment isn't the one with the most clever new architecture—it's the one that leverages existing, tested code to reduce the surface area for future bugs.