Why I use Claude Code

# Why I use Claude Code

**Slug:** why-i-use-claude-code
**Category:** Tools

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Claude Code is where I go when something is broken and I don't know why.

That's probably the most honest summary I can give. It's not my fire-and-forget tool — that's Codex. It's not my UI builder — that's Lovable. Claude Code is what I reach for when a problem needs to be understood before it can be fixed, or when I'm making a decision that will affect a lot of other things and I want to think it through before touching any code.

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## What Claude Code actually is

Claude Code is Anthropic's agentic coding tool. It runs in your terminal, works directly inside your local codebase, and operates interactively — it reads files, runs commands, interprets output, and asks clarifying questions at decision points. It can handle entire features end-to-end: writing code, running tests, fixing failures, committing to a branch.

The key difference from other tools is the reasoning. Claude Code surfaces its thinking as it works. You can watch it read files, trace how it arrived at a conclusion, and redirect it before it goes somewhere wrong. For complex multi-file problems, that transparency is genuinely valuable.

It also has the deepest configuration system of any coding tool available. CLAUDE.md files auto-load at every session — project-level instructions in the repo root, personal defaults globally at `~/.claude/CLAUDE.md`, modular rules in `.claude/rules/` that load based on context. Database rules, auth rules, testing rules — each in a separate file, each loading automatically when you're working in the relevant part of the codebase.

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## Why I use it alongside Codex, not instead of it

The 2026 developer community has largely settled on the same conclusion I've reached: there's no single right answer between Claude Code and Codex. The smart approach is to use both for what each does well.

Claude Code is objectively the better model. Better code quality, deeper reasoning, stronger performance on complex multi-file tasks. The trade-off is usage — the $20/month Claude Pro plan runs out quickly under heavy daily use in a way that Codex's equivalent plan doesn't.

My practical split:

**Claude Code** for complex debugging, architecture decisions, anything involving auth or database logic, and tasks where I need to understand what's happening before anything changes.

**Codex** for clear, well-scoped tasks I can brief clearly and run overnight. Parallel execution across multiple projects.

They're complementary, not competing. One handles the thinking-heavy work. One handles the execution-heavy work.

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## The diagnosis-first rule

The most valuable thing I've learned from using Claude Code is a rule that sounds obvious but took me a while to actually follow: diagnose before you fix.

When something breaks, the instinct is to paste the error and say "fix this." What actually happens is the agent generates a fix, applies it, breaks something else, generates another fix, and you're in an infinite retry loop.

The rule: send the error to Claude Code with one instruction — *"Explain the root cause. Do not suggest a fix yet."*

Get the diagnosis. Read it. Understand what actually broke. Then ask for the fix.

Diagnosis and fix are separate steps. Claude Code is exceptional at the diagnosis step in a way that most tools aren't — it traces errors across multiple files, finds where the real problem is, and explains it in terms you can follow. Using it for this step alone, even if you implement the fix yourself, is worth the subscription.

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## What the CLAUDE.md system actually does

Claude Code's instruction file system is the most powerful thing about it for a non-developer workflow.

CLAUDE.md files are picked up automatically at the start of every session — no prompts, no setup. What you put in them defines how Claude Code behaves for the entire project.

The three-level hierarchy I use:

`~/.claude/CLAUDE.md` — global defaults. The TNDD five-step pre-flight, teaching output format, verification order. Applies to every repo I work in.

`repo/CLAUDE.md` — project-specific rules. Stack, commands, what to never touch, how migrations work, which areas need extra care.

`.claude/rules/` — modular rules that load based on context. Database rules load when I'm working with migration files. Auth rules load when I'm near authentication code. Testing rules define how verification should work.

The result: every session starts with Claude Code already knowing the rules of this codebase. No re-explaining, no "remember to be careful with the database," no hoping it reads the right files first. The discipline is structural, not a reminder.

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## Where it fits in my stack

Lovable handles new screens and visual iteration. Codex handles well-scoped tasks and overnight execution. Claude Code handles reasoning, debugging, and anything where I need to understand what's happening before changing anything.

GitHub Actions is what actually deploys to production. Claude Code writes code and commits to branches. I review and merge. CI deploys. The agent never touches production directly — that's a principle I follow with every tool, not just Claude Code.

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## The honest picture

Claude Code hits usage limits faster than Codex under heavy daily use. If you're running it constantly for hours, you'll hit the cap. The workaround I've landed on is using Claude Code for the tasks it's best at — complex reasoning, debugging, architecture decisions — and Codex for the volume work. Between the two, usage stays manageable.

The configuration investment is real. CLAUDE.md is powerful but it takes time to get right. The TNDD toolkit gives you the starting files — a working CLAUDE.md, modular rules for database, auth, and testing, and install prompts that set everything up automatically.

But even beyond the files, you need to understand what you're putting in them. The payoff is a tool that works the way you want, every session, without friction. For the kind of building I do — product-minded, non-developer, building real things that need to work in production — that's exactly what I need.

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*The TNDD AI Builder Workflow Toolkit includes the CLAUDE.md files, modular rules, and install prompt for Claude Code — sets up the full workflow in any repo in under ten minutes.*

*[Download the Toolkit]*