Refactor a Legacy Reporting Script for a Renewable-Energy Startup
Overview
What this challenge is about.
Read the existing script and identify 5-7 distinct responsibilities tangled together. Refactor into 3 layers: data loaders (CSV, REST API), transformers (pure functions over rows), and renderers (PDF, HTML). Use higher-order functions (map, filter, pipeline composition) instead of nested for-loops. Define a clear Row data abstraction (dataclass) so transformers don't reach into dict internals. Add unit tests covering 80 percent of the transformer layer. Run the refactored script against the existing baseline and prove output equality on the last 30 days of reports. Deliver the refactored source, the tests, a baseline-equivalence proof, and a 4-page write-up the team can use as a future refactoring template.
The Brief
What you'll do, and what you'll demonstrate.
Refactor a 1,200-line single-file reporting script into modular abstractions while proving output equality with the existing baseline.
Earning criteria — what you'll demonstrate
- Identify responsibilities tangled in a real legacy script
- Apply higher-order functions to replace nested-loop logic
- Design a data abstraction that isolates layers from each other
- Prove behavioral equivalence with the previous implementation
Program Fit
Where this fits in your program.
Sharpens the same skills your degree expects you to demonstrate.
Skills
Skills you'll demonstrate.
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Careers
Roles this prepares you for.
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