3 · Your First Vertical Slice

6. 10. 2026 · Slides

Materials for this seminar accumulate here: the task, the homework, links.

Demo story

Copy the whole block and paste it to your agent. We run in parallel. The Czech version below is the same story for anyone prompting in Czech.

Implement this user story.

As someone writing a post, I want to set a mood, so readers can tell a joke from a rant.

Acceptance criteria
- A post can have a mood: happy, sad, angry, or silly. It is optional.
- The mood is chosen in the form for a new post, next to the text field.
- Every post in the feed shows its mood.
- Posts without a mood look exactly as they do today.
- The mood is still there after a reload.

Implementuj tento user story.

Jako někdo, kdo píše příspěvek, chci k němu nastavit náladu, aby čtenáři poznali vtip od nadávání.

Akceptační kritéria
- Příspěvek může mít náladu: happy, sad, angry, nebo silly. Je nepovinná.
- Nálada se vybírá ve formuláři pro nový příspěvek, vedle textového pole.
- Každý příspěvek ve feedu svou náladu zobrazuje.
- Příspěvky bez nálady vypadají přesně jako dosud.
- Nálada přežije reload stránky.

Your task

Your product owner says:

People keep telling us they can't find a post they saw last week. They usually remember a word from it, or who wrote it. I'd like them to type something and see only the posts that match. Nothing fancy for now. We first want to see if people use it.

1. Write the story with your agent. Tell it: "Ask me questions until the story has no open decisions."
2. Happy with it? Save it as story.md.
3. Then: "Implement story.md." Run the loop: check, fix, learn, commit.

Done means

Your story is ready when…

• it says who wants it, what they get and why
• every acceptance criterion can be checked in the browser, yes or no
• it says what's out of scope
• it covers what happens when there's nothing to show
• your agent has no open questions left

Your feature is done when…

• someone can find the post they saw last week
• every acceptance criterion passes in production
• reviewed with the three steps, no red flags left
• you can explain every change
• a new rule in CLAUDE.md, or a reason there's nothing to learn
• merged into main, live, posted in Seminars

Homework

Both features (the mood and yours) merged and live by Sunday midnight. Post in the Seminars channel on Teams:

Live app: <URL>
Mood PR: <link>
Search PR: <link>
My rule: <the rule, or why there was nothing to learn>