Day 21 of 21
Final Build Day — something complete, tested, and live
Goal: This is the last day of the challenge. Today you use every skill from all 21 days together and ship something real that did not exist three weeks ago.
What to do
Run /session-start
Start Claude Code. Type /session-start and answer all its questions. Do not skip this step — today especially.
Write your one-page brief
In your notes, answer: what does this page do, who sees it, what one action should they take, what are the 3-5 specific sections it needs. Write this BEFORE typing any build prompt.
Use Plan Mode to map the full build
Turn on Plan Mode by cycling from default to accept edits and then to Plan Mode. Describe everything you want to build. Read the full plan before approving anything.
Build section by section with accept edits or auto if available
After the plan is approved, build one section at a time. Accept edits is the safe default. If your account clearly exposes auto mode and you want fewer interruptions, you can use it, but only after the plan is clear. Review each section before continuing to the next. Use @ mentions for precise edits.
Set /loop monitoring during the build
In a second terminal window, set up error monitoring:
/loop 10m check my project for any new errors and report them. Say "All clear" if nothing is wrong.Run /review and /launch-checklist
When the build is complete, run both checks:
/reviewTest everything on your phone
Open your site in your phone's browser. Click every button. Fill in every form. Check the layout on the small screen. Fix anything that does not work.
Merge to main
When everything works: open GitHub Desktop, switch to the main branch, and merge your build branch into it. Write a clear commit message describing what you built.
Option A only — connect your site to Netlify and go live
Skip this step if your site is already live. If this is your first time deploying: go to netlify.com and sign up for a free account using your GitHub account. Once inside, click "Add new site" then "Import an existing project." Select GitHub, find your repository, and click it. Netlify will ask which branch to deploy — select "main." Leave all other settings as-is and click "Deploy site." Netlify will show a progress bar. When it says "Published", click the URL it shows — that is your live site on the internet.
Option A only — confirm the live site works
Open the Netlify URL in your browser. Check every page — the same way you tested on your phone. Click every link. Fill in every form. If anything looks different from your local version, note the page and what is different.
Write your three sentences
In your notepad, write down three sentences: (1) What did I build today that I could not have built 21 days ago? (2) What was the hardest moment in this challenge — and what did I learn from it? (3) What am I building next? Keep these somewhere permanent. They are proof of what you can do now.
Expected result
You built something complete, tested it, and merged it. If you chose Option A, your site is live at a real URL that anyone can visit. You have proof — in writing — of what you can build now that you could not three weeks ago.
Key takeaway
- You started this challenge as someone who had never used Claude Code. You finish it as someone who can plan, build, test, deploy, automate, and recover using one of the most powerful AI tools ever built. You do not need a developer. You have the tools. Now go build something.