D8LooP - Practise Data Engineering

Preparing your workspaceloading the brief, studio & canvas…

buyersellerlistingorder

SCENARIO

You've joined Subbox, a subscription business. Users upgrade, downgrade, pause, cancel, and sometimes come back six months later. Churn goes to the board every month, and every month somebody disputes the number — because it has quietly meant three different things in three different decks.

your model must answer

01New subscriptions and cancellations per month, by plan?
02Churn rate by month, with users active on the first day as the denominator?
03New versus cancelled for one plan across the last six months?

out of scopeDiscounts · tax · dunning · win-back campaigns

This exercise’s brief could not be loaded.The guided questions and their model answers come from the review service. It looks like it is not reachable — start it with pnpm dev:api and reload.The canvas below still works, so you can model now and run the review once the service is up.

Build starts here

The brief becomes the left drawer. The canvas stays the build surface.Study is done above. Build the tables here, hit review to validate, then use follow-ups to defend the model.

Practice studio

Ctrl/Cmd + C copyCtrl/Cmd + V pasteCtrl/Cmd + Z undoDelete remove

Start with the data model, then layer system context

Use entities and relationships for the real ERD. Add notes, containers, or curated cloud shapes only when they sharpen the story you are architecting.

68%

You built the model in the Studio. Now defend it.Churn that survives an argument

Design review

The reviewer reads your model.

Preparing your workspaceloading the brief, studio & canvas…

buyersellerlistingorder

SCENARIO

your model must answer

01New subscriptions and cancellations per month, by plan?
02Churn rate by month, with users active on the first day as the denominator?
03New versus cancelled for one plan across the last six months?

out of scopeDiscounts · tax · dunning · win-back campaigns

Build starts here

The brief becomes the left drawer. The canvas stays the build surface.Study is done above. Build the tables here, hit review to validate, then use follow-ups to defend the model.

Practice studio

Ctrl/Cmd + C copyCtrl/Cmd + V pasteCtrl/Cmd + Z undoDelete remove

Start with the data model, then layer system context

Use entities and relationships for the real ERD. Add notes, containers, or curated cloud shapes only when they sharpen the story you are architecting.

68%

You built the model in the Studio. Now defend it.Churn that survives an argument

Design review