Vandebron Mobile Developer Take-home Assessment

Thanks for applying to Vandebron — if you've made it this far we already think you're pretty great.

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Setup

1. yarn
2. yarn start — scan the QR code with Expo Go on your phone, or press i / a for simulator

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The task

You're working on a mobile energy consumption calculator. The existing code is a starting point — there are bugs to find, features to build, and plenty of room to make it your own.

The goal screenshot below is a reference, not a strict spec. Make it your own.

Where you're starting	Reference

Areas to focus on

Pick what you'd like to focus on and implement those.

• Fix the bugs — there are several in the existing code. Find and fix what you can.
• Implement ProductSelector — currently a stub. Users should be able to pick between electricity-only or electricity + gas.
• Calculate consumption — estimate usage from the inputs. Return type: { electricity: number, gas?: number }. Bigger house and more residents = higher consumption; solar panels reduce electricity. Gas should only appear when the electricity + gas product is selected.
• Make it production-ready — there are things you'd want to clean up before shipping.

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Notes

• The "Ok →" button doesn't need to navigate anywhere.
• External libraries are fine.

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Run tests

yarn test

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Submitting

When you're done:

1. If anything is broken or intentionally left incomplete, add a brief NOTES.md so we don't mistake it for an accident.
2. Zip up the project with the .git folder included and share via Google Drive, Dropbox, or similar.

We'll walk through your changes together in the interview — be ready to talk about the decisions you made.