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Hard

Compare Prompt Versions Safely

Design an experiment workspace for comparing prompt changes on a fixed evaluation set before a new version reaches production.

Desktop web

The brief

Understand the problem

Background

Prompt edits can improve average results while causing regressions for rare or sensitive cases. A credible experiment needs locked versions, representative inputs, blinded review, cost context, and a decision record rather than a gallery of appealing examples.

User context

Yuki maintains a customer-email summarizer. A shorter prompt reduces latency, but early checks suggest it sometimes omits refund deadlines and exposes internal notes in the customer-facing summary.

Product problem

A product team needs to compare two prompt versions under controlled conditions and decide whether to ship, revise, or stop based on explicit quality and safety criteria.

Objective

Create experiment setup, blinded result review, metric analysis, and release decision for one prompt change.

What to design

Define the experience

Required experience

  • Lock a baseline, candidate, model, parameters, and evaluation set
  • Define quality, safety, latency, and cost criteria before running
  • Review paired outputs without version identity bias
  • Record a release decision with failures and follow-up ownership

Screens and states

  • Experiment setup
  • Blinded comparison
  • Results analysis
  • Release decision

Core user flow

Follow the critical path

  1. 01

    Yuki selects the production prompt as baseline and adds the shorter candidate

  2. 02

    She chooses a fixed set containing refund deadlines and restricted internal notes

  3. 03

    Reviewers compare randomized output pairs against a shared rubric

  4. 04

    Results show lower latency but two critical privacy failures in the candidate

  5. 05

    Yuki stops release, assigns a revision, and preserves the run for comparison

Product rules

Requirements and constraints

Requirements

  • Version prompts, models, parameters, tools, evaluation inputs, and rubric together
  • Prevent editing any locked experiment input after a run begins
  • Randomize or blind output identity where the evaluation permits
  • Show aggregate metrics alongside every severe failure and reviewer disagreement
  • Require explicit ship, revise, or stop criteria and an accountable decision owner

Constraints

  • Evaluation data may contain restricted customer examples
  • Small samples cannot support precise claims about production performance
  • Prompt text may be visible only to authorized experiment owners

Reality check

States worth considering

A provider changes the selected model during the experiment window
A reviewer recognizes one version's output style
Outputs fail to complete for only one variant
Average quality improves while a critical safety criterion regresses

Ready-to-use content

Mock data

Use this content to test hierarchy and realistic data states. You can expand it when the concept needs more depth.

Success criteria

  • Refund deadline recall at least 95%
  • Zero internal-note exposure
  • Median latency under 2.0 seconds
  • Median run cost under $0.03

Evaluation set

  • 40 routine cases
  • 12 refund-deadline cases
  • 8 restricted-note cases
  • 10 multilingual cases

Finish line

What to deliver

  • Four desktop screens covering a controlled prompt experiment, blind review, and stopped release

Optional direction

Visual resources

Use these as a starting constraint if you want one. They are not part of the required solution.

Color palette
#1C1B19
#C7B89F
#649853
#735D5F
#87759D
Font pairing
MontserratDomine

Montserrat & Domine

Clear interface writing gives people the confidence to understand what changed and decide what to do next.

Icons
Illustrations