Bob Browning's blog

In my last post, I asked Claude Code to modify an existing program. This time, I had it write one from scratch.

The task was straightforward. Fintechbenchmark.com is a structured catalogue of fintech products with three levels of indexing, from business area down to product category. I wanted an index page that lists all three levels, indented and linked to the relevant pages — useful for both visitors and search engine crawlers.

It took me a few minutes to write the specification. Claude Code produced the working program in two minutes and twenty seconds. But it didn’t stop there — it also added the program to the routing table, so I could test it immediately. It worked first time.

A couple of small touches impressed me. I hadn’t specified a page title, so it created one. It also spotted and used a language file I’d built into the codebase — a feature that lets us customise text across the site — and updated the schema and populated it with sensible values. That’s not something I asked for; it just figured out the right thing to do.

What I Learned: the Importance of CLAUDE.md

The more valuable lesson from this exercise was about a file called CLAUDE.md. This is created when you install Claude Code, and it’s where you describe your project’s architecture in Markdown format. Think of it as a briefing document that Claude Code reads before it touches anything.

I wanted the generated code to be consistent with the rest of the site, so I gave Claude Code a selection of existing files I considered representative and asked it to analyse them and document the coding standards it found. It then updated CLAUDE.md with those standards.

After reviewing its analysis, I made a few manual edits. It had missed two things: every function in my codebase has a JSDoc header, and I like plenty of inline comments. The code it produced was otherwise well-structured — but those two things weren’t there because I hadn’t told it about them.

That’s the key lesson: CLAUDE.md is only as good as what you put into it. The output quality is directly tied to how thoroughly you’ve described your standards and preferences. Get that file right and Claude Code will follow your conventions consistently.

Where Next

I’m moving forward with noticeably more confidence now, ready to use Claude Code for more complex tasks. Watch this space.