From a 3-Hour Claude Code Workshop to Building In-House Apps: Three Client Stories

Over the past few months, we’ve seen a sharp rise in requests like “We want our team to be able to use Claude Code” and “Could you run a workshop for us?”

Because of the word “Code” in its name, Claude Code is often seen as a tool for engineers. In practice, though, it’s an AI that reads, creates, and organizes the files on your computer when you simply ask in plain language. It’s often most valuable for people who don’t program at all.

In this article, we’ll briefly walk through our introductory workshop, then share stories of participants who went on to build their own business apps after the workshop.

What the Workshop Covers: Only the Very Basics

The workshop runs three hours and uses the Claude desktop app. Our tagline: “You won’t write a single line of code. In three hours, you’ll become someone who can hand work off to AI.”

Time	Content
10 min	Why Claude Code? (Chat vs. Cowork vs. Code)
30 min	Setup (install the app → sign in → open the Code tab)
15 min	Touch the terminal — just once (create and delete a folder)
50 min	Give instructions (create, edit, and delete files; have Claude read and organize PDFs)
25 min	Teach Claude your way of working with CLAUDE.md
25 min	Wrap-up and finale (build a simple business app)
15 min	Try it on your own work / Q&A

The Key Lesson: “Where Should Claude Work?”

What we spend the most time on isn’t actually how to use AI — it’s choosing a working folder.

Claude Code works inside the folder you choose. In the workshop, we use this analogy:

Chat is a help desk: it answers you on screen
Cowork is an office colleague: you can hand off tasks like preparing documents
Code is a tradesperson who comes on site: it goes straight into your folder and does the work

Before you call a tradesperson, you decide the job site address. That’s the first move, every time.

To build that habit, we have participants open the terminal just once and create a folder called “ai” with mkdir ai. Once they’ve got the feel of “choose a place, then give a command,” we leave the terminal behind. Everything after that is done in plain language.

Ask in Plain Language, Then Read the Confirmation

Once a working folder is selected, you just give instructions:

“Create a file called self-intro.txt” → the file appears in the folder
“Read the invoice PDF and tell me the amount and due date” → no attachment needed; Claude reads it on its own
“Rename the three PDFs as Date_Vendor_DocumentType_Amount” → names that require reading the contents are applied all at once
“List their contents as a CSV that opens in Excel” → double-click and Excel opens it

Before changing any file, Claude always asks for confirmation. We also build the habit of “Don’t click Allow without reading. Take one second to read.”

Teaching Claude Your Way of Working with CLAUDE.md

In the second half, participants experience how placing a memo called CLAUDE.md in the working folder makes Claude read it before every task.

We start with something playful: we have Claude write “Always reply in Osaka dialect.” In a new session, Claude greets everyone with “Maido!” and the room relaxes. Then, for the real lesson, we have it record internal rules like “Payments of ¥100,000 or more require department manager approval” — and Claude starts applying those rules without being told.

The workshop ends by asking Claude to “build a payment management app,” producing a simple app with input, list, edit, and delete functions.

After the Workshop, Participants Are Building Their Own Apps

That’s all the workshop teaches. We don’t teach programming syntax or app development processes.

Yet one of the most common messages we receive afterward is “I built it myself.” Building on what they learned — choose a folder, ask in plain language, read the confirmation — participants ask Claude Code itself whenever they get stuck, and build what their business needs.

Here are a few examples.

Case 1: A Self-Built System for Managing Lease Contracts Across 96 Stores

Restaurant group with ~2,000 employees / General Manager (40s)

Of the company’s 96 stores, those operating in leased properties had their lease contracts managed by hand. Every time someone needed to check a renewal date or terms, it started with digging through paper and files.

After the workshop, this participant used Claude Code to build a lease contract management system on their own. It’s something they had long wanted — and instead of relying on the IT department or an outside vendor, the person who knew the operations best made it real.

Case 2: In-House Sales Management Software for the Lumber Industry

Lumber dealer & architectural design office / CEO (40s)

The company had been using an industry-specific packaged software for sales management, but honestly had some frustrations with it.

So they took on in-house development and built sales management software tailored to their own operations. “If it works out, we might be able to sell it to others in the industry.” Software built by someone who knows the business inside out can be valuable to peers facing the same challenges.

Case 3: Turning Consulting Expertise into a Subscription Web Service

Overseas expansion consulting / Founder (40s)

Until now, consulting meant selling expertise by the hour. The hours you can work set the ceiling on your revenue.

This participant used Claude Code to build a web app that delivers that expertise on a subscription basis — a case where the workshop became the starting point for a new business.

Why Can “Just the Basics” Take People This Far?

What all three cases have in common is that the thing they wanted to build was already in their heads.

They knew the business problems and the features they wanted better than anyone. What was missing was a way to turn that into something real.

Claude Code provides that way, in plain language. The workshop only instills a minimal set of habits:

Choose the place (which folder Claude works in)
Ask in plain language (state the purpose, the target, and what “done” looks like)
Read the confirmation (take one second to see what Claude is about to do)

With those three habits in place, people can keep going by asking Claude, “What should I do next?”

Of course, AI can make mistakes. The workshop also covers safety ground rules — always verify important details like amounts and dates yourself, and don’t point Claude at a folder full of important files right away.

Summary

Our introductory Claude Code workshop teaches only the basics: choose a folder, ask in plain language, read the confirmation
Even so, participants are building their own business systems and new-business apps afterward, asking Claude as they go
We’re entering an era where the people who know the work best can build their own tools

Interested in a Claude Code Workshop?

We tailor the content to your needs — whether you want to train several team members, adapt the material to your own business processes, or get support with development after the workshop. Feel free to get in touch.