The Build

Where the plan becomes real, one checked step at a time

Now Claude writes the code, working down the plan one small piece at a time. Your job isn't to read it. It's to check each piece does what the spec promised, before moving to the next. Small steps, verified as you go, so a wrong turn costs minutes and not the whole project.

The specThe planThe build
Your job while it builds

You don't read the code. You use it.

When Claude finishes a piece, you don't check it by reading code, you check it the way you'd use it. Three questions, every time.

Claude: "The triage list is done."
Your ten-second check before you say "next":
01
Open it. Does the right thing actually show up?
02
Does it match what the spec promised?
03
Click the main thing. Does it do what you expected?
If yes, move on. If no, you caught it now, while it's a five-minute fix and not a finished app built on a wrong turn.
And here's mine

What building actually looks like

This is the real trail of Retention Pulse getting built. Not one giant "make me an app", but dozens of tiny, named, finished steps, each checked before the next. Read it top to bottom and you can watch the app appear.

Building the Today board
featthe class-roster core, with tests
featread the day's bookings + categories
featthe board cards, colour-coded, wired to the member peek
featthe page renders the class roster + a freshness stamp
Catching the things that broke
fixmobile calendar cells balloon into tall ovals on iPhone
fixrender class times in the studio's timezone, not UTC
Letting the manager act
featclick-to-message deep-link into Grow (all 566 members)
featsnooze + mute, so handled members leave the list
Getting it online, safely
featGoogle sign-in
shippackage it up for the server
shippush-to-deploy, so saving the code puts it live
Then a review, folded back in
reviewengine-truth fixes from the code review (the next tab)

Forty-odd steps like these built the whole app. Each one small enough to finish and check in a sitting. That's the secret: not big leaps, just a lot of small, sure ones.

Steering it while it builds

Building is a conversation. Here's how to talk to it.

When a piece comes back wrong, or it drifts, or an error pops up, you don't need code to fix it. You need clear, specific, early feedback, the same way you'd steer any good collaborator.

A real Claude Code session mid-build: the plan with pause-points, the tools menu, and the preview's annotate and select tools.
A real session, mid-build: Claude's plan with its pause-points at the risky steps, the tools menu (Preview, Diff, Terminal, Files, Plan), and the preview's annotate and select tools, top right. The whole cockpit in one frame.
01
Say what you see, not "it's broken"
Instead of"It's broken."
Try"When I click a member, nothing opens. I expected the detail panel."
02
Be specific about what's off
Instead of"I don't like it."
Try"The spacing's too tight after the heading. Give it more room."
03
Catch it early, don't let it run
Instead ofletting it go the wrong way and fixing it all at the end.
Try"Hold on, that's not the direction. Let me redirect before you go further."
04
Add, don't replace
Instead of"No, do this instead." (and lose the good part)
Try"Keep what you've got, and also add this."
05
Hand it the error
Instead oftrying to read the red error text yourself.
Trypasting the whole error in: "this came up, can you fix it?"
06
Keep the north star
Instead ofchasing every new idea as it pops up.
Try"Does this still serve the goal: show me who to call today?"
The shortcut

Don't describe it. Point at it.

Your live preview has two tools that let you give feedback without fumbling for words. Reach for these constantly.

  • Annotate — draw straight on the preview to circle or mark what's off.
  • Select element — click the exact thing, and Claude knows precisely what you mean.
×
Annotate preview Select element ⇧⌘S
And the common snags, with your one-line move:
  • It does too much at once"Slow down. One piece at a time."
  • It builds things you didn't ask for"Keep it simple. Just do this one thing."
  • It assumed something you didn't want"Actually, I meant this, not that."
  • It lost the threadpoint it back to your progress note.
  • An error appears (red text)don't panic. Paste it in. It'll fix it.

None of this is technical. Honestly, it's exactly how this guide got built: small, specific corrections, one after another, until it was right.

Built, step by step

Every one of those steps got written down as you went

Which is how you come back next week and pick up exactly where you left off, instead of re-explaining the whole thing. That's the next tab.

Up next · The Progress