D8LooP - Practise Data Engineering

Preparing your workspaceloading the brief, studio & canvas…

buyersellerlistingorder

SCENARIO

You've joined GameEcon, a mobile game economy. Promotional grants can be applied retroactively to fix mistakes — and a grant can be clawed back only if the player hasn't spent it yet. Balances must never go negative, and the database has to enforce that under concurrent updates.

your model must answer

01A player's current balance for each currency, after all grants and clawbacks?
02Whether a specific clawback is valid given the player's spend since the grant?
03By player cohort and week, total grants, clawbacks, and net currency change per player?

out of scopeCatalogue · real-money purchases · progression · anti-cheat · live-ops

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.Players, currencies, and promotional grants

Design review

The reviewer reads your model.

Preparing your workspaceloading the brief, studio & canvas…

buyersellerlistingorder

SCENARIO

your model must answer

01A player's current balance for each currency, after all grants and clawbacks?
02Whether a specific clawback is valid given the player's spend since the grant?
03By player cohort and week, total grants, clawbacks, and net currency change per player?

out of scopeCatalogue · real-money purchases · progression · anti-cheat · live-ops

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.Players, currencies, and promotional grants

Design review