Design a fair take-home assignment with a grading rubric and time-box guardrails

You are a senior engineering interviewer who designs take-homes that are fair, time-bound, and signal-rich. A take-home is a candidate's unpaid evening — treat their time as precious.

Role context:
- Role / level: [TITLE, LEVEL — e.g. 'Senior Frontend Engineer']
- The real on-the-job signal that matters: [LIST — e.g. 'API integration, state mgmt, accessibility, code clarity']
- Tech stack the candidate may use: [LANGUAGES / FRAMEWORKS / OR 'THEIR CHOICE']
- Target time box (must be honest): [E.G. '3-4 hours max']
- Format: [BUILD A SMALL APP / EXTEND A REPO / WRITE A DESIGN DOC / DEBUG A PROVIDED REPO]
- What you must NOT request: [E.G. 'no proprietary data', 'no production-scale feature']

Design the assignment with:
1. A one-paragraph brief the candidate reads first: the scenario, the deliverable, the time box, and the 'we are evaluating X, not Y' line so they optimize for the right thing.
2. The concrete task — scoped to the stated time box, with a clear definition of done. If the task cannot fit the time box, cut scope, not the box.
3. What to submit and how (repo, zip, README expectations) and what NOT to spend time on (no need to deploy, no need to gold-plate).
4. A graded rubric: 4-6 criteria, each with 'Below bar / Meets bar / Exceeds bar' described in observable, concrete terms (e.g. 'tests cover the happy path AND one edge' = Meets). No criterion rewards only aesthetics or only volume.
5. A 'we do not penalize' list: time spent, choosing a familiar stack over a fancy one, asking clarifying questions, reasonable assumptions stated in the README.
6. Anti-cheat and ethics notes: how you confirm it is their work without treating them as guilty (a short walkthrough call, not surveillance), and a reminder that the assignment must not be real production work the company will use.

Fairness rules:
- The time box is a ceiling, not a floor. A candidate who hits 'Meets bar' in 2 hours is stronger than one who grinds 8.
- Do not request anything that gives the company shippable product for free. The deliverable is an interview, not unpaid labor.
- Make the task role-realistic and free of hidden traps that only insiders would know.
- Flag any part of the task with disparate-impact risk and propose a fairer alternative.

Output: candidate-facing brief, the task spec, submission guide, the graded rubric, the do-not-penalize list, ethics notes.

Success signal: the output is good only if the task honestly fits the stated time box, the rubric is observable at every bar level, and the deliverable is explicitly not free work for the company.