Active time: Approximately 25–35 minutes.

Today’s outcome: Test the app, use the results to choose one change or no change, then run the same tests again.

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**Quick links: LinkedIn lessons · WhatsApp group · The Builder Course website .

Setup . Day 1 . Day 2 . Day 3 . Day 4 . Day 5**

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💡 Using Claude Code?

You can complete this lesson with Claude Code in the same challenge folder.

Replace AGENTS.md with CLAUDE.md everywhere it appears inside copied prompts. The remaining steps are the same. The supported setup and demonstrations use Codex.

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Yesterday, you recovered from a controlled error.

Today, test the whole Task Prioritizer before you decide whether to change it.

Do not begin with suggestions. Test first, then use your results to choose one small change or no change.

Why this matters

“It seems to work” is not the same as testing.

A useful test records what you did, what you expected and what happened. That gives you something specific to act on.

Test before changing the app so you can:

Today’s improvement sequence is:

Test → record evidence → choose one weakness → approve one change → retest

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Before you begin

Open the same challenge folder in VS Code.

Confirm that you can see:

Now open the app from index.html:

  1. In the VS Code Explorer, right-click index.html.
  2. On a Mac, select Reveal in Finder. On Windows, select Reveal in File Explorer.
  3. Double-click index.html in Finder or File Explorer.

The Task Prioritizer should open in your default browser. If it is already open, refresh the page before continuing.

If the app is still broken after Day 5, stop here. Return to the Day 5 diagnosis and repair steps first.

Start by testing the app yourself and recording what happens. Do not ask the coding agent to suggest improvements yet.