A fictional logistics team needs a queue diagnostics file. Build duplicate detection and log merging, compact cancelled stock, then inspect and repair linked routes. The dataset is the set of queue fixtures shown at each step. Deliver one source file containing all six tested functions. A cyclic route is the final incident check; equal job values alone do not prove a cycle.
Build a small source file that another engineer can reuse. Each step adds one function with its own contract and tests. Keep earlier functions while you add the next one.
The final file is your deliverable.
Check each helper as you go. An earlier function can still contain a defect after a new helper passes, so review the combined file before handing it over.